PHILADELPHIA — Philadelphia police say they believe they have in custody everyone involved in a shooting that critically wounded a police officer after a traffic stop.

The 31-year-old officer and his partner stopped a car carrying four people shortly before 8 p.m. Saturday in the Kensington neighborhood of northeast Philadelphia, the city’s police commissioner, Kevin Bethel, told reporters late Saturday night.

The officers were taking inventory of the vehicle when they saw someone with a gun holster, Bethel said. That person fled, firing three times and hitting one officer in the neck, he said. The wounded officer was taken to Temple University Hospital in critical condition, Bethel said.

“I often come here with a lot of anger about what my men and women must endure," Bethel said. But he said he had just come from a gathering of 75 to 100 police personnel in which they held hands to pray for the officer, and he was coming before the public in this instance to ask people across the city to do the same.

The shooting suspect and all of the people who were in the car “as well as a person of interest who was involved in the shooting” were in custody, Bethel said.

“We believe all responsible are in custody,” he said, telling reporters that no one else was being sought.

Bethel said the officer’s partner “definitely” returned fire, but there was no initial indication that the wounded officer had fired.

Mayor Cherelle Parker said in a social media post that the officer, who has been on the force for 6 1/2 years, was “on life support” on a breathing machine. She also asked residents to pray for “a husband, a father, and a son” who was doing “a noble job under very tough circumstances.”

"He didn’t expect that he would be in a fight for his life,” she said.

Gov. Josh Shapiro said in a social media post Sunday that he and the first lady were joining others in praying for the wounded officer.

“His family is in our thoughts — as are his fellow officers, who were forced to rush one of their own to the hospital last night,” he said.

Over the past eight months, gunfire has killed one Philadelphia officer and wounded eight others.

In October, Officer Richard Mendez was killed and another officer wounded in a shooting while investigating a suspected car break-in in a parking lot at Philadelphia International Airport. Three New Jersey men are awaiting trial in that case. Earlier in the month, three officers were wounded in a shootout at a northeast Philadelphia home after an argument reportedly over a video game erupted in gunfire.

In December, an exchange of gunfire after the pursuit of a shooting suspect wounded two officers. In January, an officer was shot in a corner store and a suspect was killed by another officer. A few days later, an officer was shot in a hand while serving a warrant.

In neighboring Delaware County in February, authorities said two officers were wounded by gunfire from an East Lansdowne home before it burned to the ground. Six sets of remains were recovered, and the suspect and four relatives — two adults and two juveniles — died of gunshot wounds while one child died of smoke inhalation, authorities said.