Three Philadelphia police officers opened fire Saturday evening in Frankford and critically wounded a man after he appeared to pull a handgun, police said.

Department spokesman Lt. Frank Vanore said two uniformed officers on patrol saw Carnell C. Williams walking north on North Griscom Street with what they determined was a 9mm Beretta in his waistband. When Williams saw them, Vanore said, he started running.

Around 7:22 p.m. the officers called for assistance and pursued Williams on foot to a vacant lot at 4936 N. Griscom St., where they were joined by a third officer.

When Williams pulled out his weapon, Vanore said, all three officers ordered him to drop it, and fired 10 rounds when he failed to do so.

Williams, 29, of the 2000 block of Lardner Street, was struck in the left shoulder by a single bullet and fell to the ground, Vanore said. Officers retrieved the Beretta semiautomatic handgun with 15 rounds at the scene, he said.

Williams, who Vanore said has been arrested multiple times for robberies and drug offenses, was taken to Aria Health-Frankford Campus and transferred to Thomas Jefferson University Hospital, where he was in critical condition.