Authorities say police officers came under fire in Philadelphia for the second night in a row, but no one was injured.

Police says officers noticed a 19-year-old man apparently smoking marijuana shortly before midnight Saturday in an area of central Philadelphia packed with restaurants, shops and clubs.

Officers pursued him to a nearby street, where authorities allege that he opened fire, discharging at least three shots. The officers didn't return fire. They arrested him and recovered a gun.

Several people were injured, several critically, in unrelated shootings overnight.

The confrontation came a day after an officer was ambushed in her car in west Philadelphia and a university police officer and four other people were shot before the gunman was killed. One of the people shot later died.