An off-duty Philadelphia police officer was in serious condition and a friend was dead after the two were shot during a robbery attempt in the city's Hunting Park neighborhood tonight.

Police later shot a man who matched the description of one of the assailants and arrested a man with him.

The officer, Martin P. Campbell, was hit in his left leg and taken to Temple University Hospital in critical condition after the bullet "nicked" an artery, according to Lt. Frank Vanore, a police spokesman. By the end of the night, he was upgraded and stabilized at the hospital, where Mayor Nutter and Police Commissioner Charles H. Ramsey were "hopeful" that the 23-year-old officer would fully recover. He was still in surgery shortly before midnight.

The body of Campbell's friend, identified by relatives as Rasheen Allen, was covered by a brown blanket on the 4400 block of Marshall Street until it was taken away, around 10 p.m.

His mother, Nadra Allen, was nearby, sobbing and yelling.

"That's somebody else, right? That's somebody else, right?" she shouted as relatives tried to comfort her.

She was frustrated that she was not allowed to see her son's body.

Police said two men had tried to rob Campbell and Allen - two longtime friends - and a third friend around 7:15 p.m., leading to the shooting.

Roughly three hours later, police responded to a call about two men fitting the assailants' descriptions in the 1100 block of West Venango Street, a few blocks from the Temple hospital. After police stopped the men, one pulled a gun, and an officer shot and wounded him, Vanore said.

The man was taken to Temple with a gunshot wound to the groin, and there was no word on his condition tonight. The second man was arrested.

Police had not determined if the men were the suspects in the shooting of Campbell and his friend.

A police chopper swept a spotlight over West Venango Street late tonight as police searched the area.

One relative said Rasheen Allen was about 29. His family said Allen and Campbell were childhood friends who both grew up on the block.

Allen had a son about 6 years old, relatives said, and was on disability from a job at SEPTA due to a blood-clotting condition.

Campbell is single and has no children. His mother and father were at the hospital tonight. He has been with the police force for two years and serves in a district that covers Manayunk and Roxborough.

The shooting happened as Campbell, Allen, and their friend were getting out of a car on Marshall Street. Two men in hoodies approached and announced a robbery, according to police.

The street is lined with two-story homes, with stone and brick facades and small front porches.

Campbell didn't have a chance to draw his gun, police said. Officials did not identify the two men with Campbell, other than to say both were in their 20s.

Nutter called the shooting another example of "senseless violence," adding that he was hopeful that Campbell would have a full recovery.

"Hopefully he pulls through," Ramsey said at a brief news conference shortly after 9 p.m. outside the entrance to the hospital's emergency department.

It was the fourth time a Philadelphia officer was shot this year, Vanore said. One shooting, in February, killed Officer John Pawlowski.

The two assailants were last seen fleeing south on Marshall Street, Vanore said. The shooter, he said, was about 6 feet tall and thin; wore a white hooded sweatshirt, blue jeans, and brown boots; and used a silver pistol.

His accomplice was around 5-foot-6 and had a goatee. He wore a black jacket with blue jeans.

Allen's family said he and Campbell had been close growing up on a block where neighbors looked out for one another. Several people on the scene called the street "The Block That Cares."

"We're like family on this block," said Shajeah Hasson, a cousin of Allen's. She said Campbell was "his homie, his brother."

Officers at the Fifth District were not talking to reporters tonight, but were seen watching television coverage of the shooting.

Police asked anyone with information on the shooting to call the Homicide Division at 215-686-3334 or 215-686-3335.