Dzhokhar Tsarnaev, the suspect in the Boston Marathon bombings who was seriously wounded and is unable to speak, is awake and writing responses to authorities' questions, according to Tweets by the ABC and NBC news networks.

The 19-year-old suspect is in the intensive care unit of Beth Israel Deaconess Medical Center, and making sporadic responses, the ABC news network reported on its Twitter feed.

NBC's Pete Williams and CNN are also reporting Tsarnaev is writing answers to questions from law enforcement, citing anonymous sources.

Tsarnaev took a gunshot in the mouth that exited the back of his neck, Boston Police Commissioner Ed Davis said in a CBS' "60 Minutes" interview.

He also suffered a gunshot wound to the leg, Davis said.

Massachusetts Gov. Deval Patrick has asked residents to observe a moment of silence Monday at 2:50 p.m., the time the first of two bombs exploded last Monday near the Marathon finish line.

Tsarnaev was captured Friday night from a tarp-covered boat in a Watertown yard Friday night and remained hospitalized in serious condition Sunday.

Tsarnaev and his 26-year-old brother, Tamerlan, engaged in a wild shootout with police early Friday. Tamerlan was killed and a bloodied Dzhokhar fled the scene.

ME: No cause of death yet for bombing suspect killed during getaway

BOSTON - Massachusetts' chief medical examiner is still working to figure out exactly what killed the Boston Marathon bombing suspect who unleashed a barrage of gunfire and explosives on police before dying during a gateway attempt.

Terrel Harris of the state Executive Office of Public Safety and Security says the medical examiner hasn't determined the cause of death of 26-year-old Tamerlan Tsarnaev.

Tsarnaev and his brother, 19-year-old Dzhokhar, are accused of planting two explosives near the marathon finish line Monday, killing three people and injuring more than 180. A motive remains unclear.

The older brother was killed during a getaway attempt early Friday. Police say he was run over by a car driven by his brother as he fled the gunfire. The younger brother was captured Friday night after a gunbattle with police and remains hospitalized in serious condition.

FBI: No contact after bombing

WASHINGTON - The FBI is disputing a claim by the mother of the suspected Boston bombers, who said the bureau had spoken to the older brother after the bombs exploded at last Monday's marathon.

At FBI headquarters in Washington, spokesman Michael Kortan says the bureau's 2011 interview with Tamerlan Tsarnaev (tsahr-NEYE'-ehv) was the only FBI contact with him.

Kortan is standing by the bureau's public statement from Friday in which the bureau described that interview. That statement says the FBI did not learn of the identities of the bombing suspects, Tamerlan and his brother, Dzhokhar (joh-KHAR'), until Friday, the day Tamerlan was killed.

The brothers' parents in Russia have insisted that the FBI continued to monitor Tamerlan after the 2011 interview and say both of their sons were set up.

Brothers did not have gun permits

CAMBRIDGE, Mass. - A Massachusetts police official say the brothers suspected of bombing the Boston Marathon before having shootouts with authorities didn't have gun permits.

Cambridge Police Commissioner Robert Haas tells The Associated Press in an interview Sunday that neither Tamerlan Tsarnaev (tsahr-NEYE'-ehv) nor his brother Dzhokhar had permission to carry firearms.

He says it's unclear whether either ever applied and the applications aren't considered public records.

But he says the 19-year-old Dzhokhar (joh-KHAR') would have been denied a permit because of his age. Only people 21 or older are allowed gun licenses in Massachusetts.

The suspects were also accused of hijacking a Mercedes on Thursday night.

Haas says the pair didn't release the driver, but he escaped when he was left alone while the two men entered a convenience store.

More attacks intended

Commissioner Ed Davis told CBS' "Face the Nation" on Sunday that authorities found an arsenal of homemade explosives following a gun battle between police and the suspects last week in Watertown, Mass.

Davis says authorities have reason to believe 19-year-old Dzhokhar Tsarnaev (joh-KHAR' tsahr-NEYE'-ehv) and 26-year-old brother Tamerlan "were going to attack other individuals."

He says the scene of the gun battle was "loaded with unexploded improvised explosive devices that actually we had to point out to the arriving officers and clear the area."

He said on "Fox News Sunday" authorities cannot be positive there aren't more explosives that haven't been found. But he says the people of Boston are safe.

Tamerlan died in the gunbattle with police in Watertown.

Moment of silence Monday

BOSTON - Massachusetts Gov. Deval Patrick is asking residents to observe a moment of silence Monday at the time the first of two bombs exploded near the finish line of the Boston Marathon.

The one-minute silent tribute to victims is scheduled for 2:50 p.m. and will be followed by the ringing of bells in Boston and elsewhere in Massachusetts. It marks one week since the attacks that killed three people and wounded more than 180 others.

Patrick issued the call Sunday in a joint appeal with Boston Mayor Thomas Menino and One Fund Boston, a charity set up to help victims of the bombings.

Patrick and Menino say they are humbled by support from the public and the business community.

Tamerlan Tsarnaev's training

The chairman of the House Intelligence Committe, Rep. Mike Rogers, R-Michigan, said Sunday that he believes Tamerlan received training while in Russia for six months in 2012 and that he may have traveled using an alias. Rogers made his comments on NBC's 'Meet the Press'.

Video of suspect

WASHINGTON (AP) — Surveillance video from the Boston Marathon attack shows one suspect dropping his backpack and calmly walking away from it before the bomb inside it exploded, Massachusetts Gov. Deval Patrick said Sunday.

Davis says "this was as dangerous as it gets in urban policing."

Dzhokhar Tsarnaev has throat injuries and was "intubated and sedated," according to CNN, citing an unnamed source briefed on the case. Davis said Sunday that the teenager had not been interviewed yet by investigators.

The video clearly puts 19-year-old Dzhokhar Tsarnaev at the scene of the attack, Patrick said on NBC.

"It does seem to be pretty clear that this suspect took the backpack off, put it down, did not react when the first explosion went off and then moved away from the backpack in time for the second explosion," Patrick said. "It's pretty clear about his involvement and pretty chilling, frankly."

He added, however, that he hasn't viewed all the tapes but had been briefed by law enforcement about them.

Suspects' motivation?

The governor of Massachusetts says he has no idea what motivated the terrorists who exploded two bombs near the finish line of the Boston Marathon.

Speaking Sunday on CBS' "Face the Nation," Deval (deh-VAL') Patrick said it's hard to imagine why someone would deliberately harm, quote "innocent men, women and children in the way that these two fellows did."

Patrick also said law enforcers believe the immediate threat ended when the police killed one of the alleged terrorists and captured the other. The two men were brothers whose family had come to the U.S. from Russia.

Suspect's Miranda rights

WASHINGTON - The chairman of the House Intelligence Committee believes there's enough evidence against the suspected Boston marathon bomber to convict him.

Rep. Mike Rogers of Michigan tells NBC's "Meet the Press" that he's not worried that the government has decided against reading the suspect his Miranda rights. He says FBI agents need to know whether there are other bombs more than they need to use in court what the suspect might tell them.

Rogers, a former FBI agent, says there is so much evidence against the suspect that a conviction should be easy.

There was no immediate word on when Dzhokhar Tsarnaev might be charged and what those charges would be, although NBCNews reported that charges could come today.

Mayor: Suspects acted alone

WASHINGTON - Boston Mayor Tom Menino says information he has indicates that the suspects in the Boston Marathon bombing acted alone.

Menino tells ABC's "This Week" that he agreed with the decision to lock down Boston all day Friday, based on information officials had at the time.

He tells ABC's `This Week" that a pipe bomb was found at another location and that another person was taken into custody. The mayor did not elaborate.

One suspect, Dzhokhar Tsarnaev (joh-KHAR' tsahr-NEYE'-ehv), is in the hospital in serious condition. His older brother, Tamerlan, died in a police shootout Friday.

Vigil for MIT officer

A vigil was held late Saturday in Massachusetts for an MIT police officer authorities say was shot and killed by the alleged Boston Marathon bombers.

Hundreds turned out Saturday night in Wilmington to honor 26-year-old Sean Collier, who grew up in the town about 15 miles north of Boston.

Authorities say Collier was shot in his cruiser Thursday night on the MIT campus in Cambridge. He lived in Somerville and was preparing to become a police officer in that city.

The Boston transit agency on Sunday released a photo of Collier with Richard Donohue, the 33-year-old transit police officer who remains hospitalized after authorities said he was seriously wounded in a gun battle with the bombing suspects.

The photo was from a 2010 graduation ceremony at the Municipal Police Officers' Academy.

Services planned for victims

BOSTON - Boston-area residents are coming together in prayer and reflection after a tumultuous week that began with the bombings at the Boston Marathon.

Cardinal Sean O'Malley will offer a Mass on Sunday to pray for those killed and injured in the attack and the later manhunt for the suspects. The service will also honor police, firefighters, EMTs and doctors who saved lives.

A Boston synagogue is opening its doors to worshippers from Trinity Church, which sits in the shadow of the Marathon finish line and remains closed. Sunday's service will be held at Temple Israel.

An interfaith service will also be held Sunday near the finish line. The Rev. Nancy Taylor of the Old South Church said worshipers will be showing solidarity with bombing victims.

London Marathon

LONDON (AP) — A defiant, festive mood prevailed Sunday at the London Marathon despite concerns raised by the bomb attacks on the Boston Marathon six days ago.

Thousands of runners offered tributes to those killed and injured in Boston on a glorious spring day in London. The race began after a moment of silence for the victims in Boston, and many here wore black armbands as a sign of solidarity.

"It means that runners are stronger than bombers," said Valerie Bloomfield, a 40-year-old participant from France.