WHITTIER, Calif.—Five people were injured, two critically, in an explosion at a food truck in Whittier July 20, authorities said.

Firefighters and paramedics were dispatched at 9:16 a.m. Saturday to the 6700 block of Greenleaf Avenue, according to a Los Angeles County Fire Department dispatcher.

Paramedics treated five people at the scene: two critical, two with moderate injuries, and one with minor injuries, the dispatcher said. It was not immediately known if all five were sent to a hospital.

The Whittier Police Department was at the scene investigating the circumstances surrounding the explosion.