A fire in a drug rehabilitation center in Lima, Peru has killed at least 20 people, according to local officials.

Another ten people were hurt at the “God Is Love” center, which reportedly used Biblical teachings to treat addicts in the densely populated San Juan de Lurigancho district.

The BBC reported that a local policeman suspected the blaze erupted after a patient’s mattress caught fire.

A local radio station RPP reported that many of the people who perished were locked in their rooms and couldn’t open the doors.

A survived patient named Gianfranco Huerta told RPP: The doors were locked, there was no way to get out.”

Another patient told RPP that he escaped the fire by jumping out the second floor.

I could just see smoke and hear screams, he said.

The cause of the fire is now under investigation by health officials.