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 two men apparently smoking marijuana late Saturday in an area of central Philadelphia that's packed with restaurants, shops and clubs.

They pursued the men to a nearby street, where authorities said one of the men opened fire, discharging four shots. The officers didn't return fire. They arrested the two men and recovered a gun.

Several people were injured 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.