A student mixing chemicals in the basement of a building at USC caused a small explosion Tuesday, but no one was injured, authorities said.

The blast was reported at 7:43 p.m. in a five-story building at 3710 S. McClintock Ave., Margaret Stewart of the Los Angeles Fire Department said. An alert issued by the university identified the building as Ronald Tutor Hall.

Another alert advised recipients to avoid a closed stretch of McClintock Avenue between Downey Way and 37th Place.

There was no structural damage to the building, which was evacuated as firefighters worked to mitigate a gas leak and a hazardous material crew investigated the explosion, Stewart said.

It was not immediately clear what type of chemicals were being used.