Nearly 23 years after his mother's death, 89-year-old Millard Braunstein stood by her graveside at Mount Carmel Cemetery on Monday morning and quietly wept.

"My mom was a beautiful lady," he said. "She didn't deserve this."

Braunstein, of Cherry Hill, wasn't mad at death or God – but, rather, at the vandals who toppled his mother's tombstone and about 100 others at the Jewish cemetery in Northeast Philadelphia's Wissinoming section overnight Saturday.

>>Click here for complete coverage of vandalism at the cemetery

"I'm so upset," he said. "This is such a terrible thing."

A steady trickle of mourners visited the cemetery Monday looking to see whether their loved one's tomb was among those desecrated, while volunteers offered assistance and officials thought through the best ways to fix the damage.

One cemetery visitor even took the time to place small pebbles on many of the broken tombstones and their bases, a Jewish custom of remembrance when visiting a grave site.

Philadelphia police, meanwhile, continued to investigate who committed the vandalism and why.

"This is an abominable crime, that appears to target these particular headstones," the department said in a statement.

Public officials from Washington to Harrisburg were swift Monday to condemn the desecration as well as a series of bomb threats directed toward Jewish community centers across the country.

White House Press Secretary Sean Spicer called the Philadelphia cemetery vandalism "cowardly destruction," and Gov. Wolf and Attorney General Josh Shapiro pledged investigative support from state law enforcement agencies.

"Any anti-Semitic act or act of intimidation aimed at Jewish institutions and people in Pennsylvania is truly reprehensible, and we must find those responsible and hold them accountable," Wolf said in a statement, adding that he had directed the state police and Office of Homeland Security to assist with the investigation and protecting Jewish institutions.

Salaam Bhatti, national spokesman for the Ahmadiyya Muslim Community, traveled to the cemetery from New York City with other Muslim men to see how they could help Monday.

Richard Levy, administrator for the cemetery, asked people to "absolutely not" try to put the toppled headstones back themselves, for fear of injury, so Bhatti said his group would provide emotional and physical support -- including guarding the cemetery gates if necessary.

"There is a rise in anti-Semitism and a rise in Islamaphobia. An attack on one faith is an attack on any faith," Bhatti said. "It's a moment of being here for each other."

John "Johnny Doc" Dougherty, leader of Local 98 of the International Brotherhood of Electrical Workers, said the union had offered to resettle the headstones, re-sod the ground, and install security cameras at the cemetery – all free of charge.

"Whatever we need to do" to help the cemetery recover, Dougherty said.

He added that his members were prepared to help as soon as the cemetery said they were needed: "If they want us there in two days, we'll be there in two days."

Meanwhile, people from around the world with relatives buried in the cemetery tried to contact cemetery staff and reporters to find out whether their loved one's tomb had been desecrated.

Levy, the cemetery administrator, seemed overwhelmed by the calls and inquiries, and said it would take him a few days to inventory the damaged stones and get back to the families.

The cemetery, which does not have surveillance cameras, has about 2,000 grave sites, Levy said. He did not know exactly how many had been vandalized but agreed with preliminary police estimates of around 100.

Bud Newman, chairman of the board of the Jewish Federation of Greater Philadelphia, said he believed well more than 100 headstones had been toppled at the cemetery.

"We have no position on motive," Newman said while touring the grounds. "We'll leave it to the authorities who are diligently looking into this and trying to do the right thing."

The federation said it will begin cleaning up the cemetery Tuesday, and asked for volunteers.

"These volunteer clean-ups will take place each day from noon to 4 p.m.," the federation said in a statement.  "Representatives from the Jewish Federation will be on hand as well as up to 50 people per hour cleaning and working to help restore this important Philadelphia landmark."

Police have not yet commented on a motive or suspects.

The Anti-Defamation League, with support from the Mizel Family Foundation, is offering a $10,000 reward for an arrest and conviction in the case. Fraternal Order of Police Lodge 5 is offering an additional $3,000 toward the reward.

A GoFundMe campaign to collect money for cemetery repairs had raised more than $17,000 as of Monday afternoon.

The vandalism at Mount Carmel was similar to vandalism the previous weekend at a Jewish cemetery near St. Louis, where vandals knocked over 154 headstones.