An explosion occurred Monday at a steel factory in Clairton, Pennsylvania, authorities said. A spokesperson for Allegheny County said a rescue operation was underway at U.S. Steel Clairton Coke Works for people trapped under the rubble.

An explosion Monday at a U.S. Steel coking plant near Pittsburgh has left people trapped under the rubble, with emergency workers on site trying to rescue them, an official said.

(Reuters) -Multiple people were injured on Monday after an explosion at a steel plant in the Pittsburgh metropolitan area, where fire crews could be seen battling flames as heavy smoke rose from the facility,