Summer in the city often means warm nights on the front step, neighbors gathered around, children playing in the street.

But any sense of calm on an East Germantown block Thursday night was violently disrupted when at least three shooters sprayed dozens of bullets through the neighborhood, striking houses, cars, and four people - including Mahaj Brown, a 6-year-old boy who was critically wounded, police said.

It was the second time in a week that a 6-year-old child was struck by stray gunfire in Philadelphia. At least five other children under age 10 have been shot in the city this year, two fatally.

Chief Inspector Carl Holmes said police were working to determine the identities of Thursday's shooters - one of whom used an AK-47, he said - and police announced a $10,000 reward for information leading to an arrest and conviction.

In asking the public for tips at a news conference, Holmes decried the shooters' apparent impulse to open fire and lamented that collateral damage from shoot-outs has become a dangerous norm in some crime-ridden neighborhoods.

"We are very concerned about any type of gunfire on our streets," he said. "Once a projectile leaves the barrel of a gun, anybody can become the victim of that weapon."

The wild shootout erupted shortly after 11:15 p.m. Thursday on the 500 block of East Ashmead Street, police said. While detectives were still investigating Friday, police said it appeared the violence resulted from a drive-by gun battle between beefing neighborhood groups.

The bullets started flying when someone in a green Chrysler minivan opened fire from the open side door on two 29-year-old men who were trying to retrieve cigarettes from a parked car, police said.

One of the men, who suffered a gunshot to his back, was treated at Einstein Medical Center, police said. The other tried to run into a nearby house but was shot several times and was listed in critical condition at Einstein.

Nearby, a 32-year-old man, who was driving a car with Mahaj, his godson, told investigators that he heard gunfire and waited for a Mercury Mountaineer from which someone was shooting to pass him, police said.

As the Mountaineer passed, someone opened fire, striking the man and the child, police said.

It was not immediately clear which shooting happened first, or why the shooters fired at any of the victims. Holmes said detectives were still investigating the motive, adding that Mahaj was an innocent victim.

"This was a wanton act of violence," he said. "Obviously a 6-year-old boy is not the intended target. I can say that with certainty."

The 32-year-old, shot in an arm, tried to drive to the hospital but flagged down a police officer who was responding to the shooting. Police took the man to Einstein in critical condition.

Mahaj was critically wounded by gunshots to his chest, a leg, and groin, police said. He was taken to Einstein and later moved to St. Christopher's Hospital for Children. He was expected to survive.

Holmes said at least 30 shots were fired from three guns, including the AK-47, a 45-caliber semiautomatic handgun, and another handgun.

Several nearby houses and cars also were struck by the barrage of bullets, including a Jeep with two people inside who escaped harm, police said. Bullet holes could be seen Friday in at least five rowhouses on the block. Several neighbors described hearing quick bursts of gunfire and took cover in their homes as the chaos continued.

"The only thing that stopped them from killing me was the brick wall," said a woman sitting on her porch with her dogs. She, like others on the block, declined to give her name out of fear for her safety.

Mahaj's grandmother Delores Melendez was distraught in an interview with 6ABC. "People's children are dying for no reason," she said. "My grandbaby is up there suffering, for what? He did nothing. He was going home."

Police on Friday were continuing to look for both vehicles from which people were shooting. Anyone with information about the shooting is asked to call 215-686-8477.