A man was injured Sunday in an explosion at a homeless encampment underneath the freeway near Potrero Hill, police said.

The 40-year-old man was reportedly cooking hash oil near San Bruno Avenue and Alameda Street about 10:36 a.m. when a fire ignited that resulted in the explosion, police said.

The man was burned on his chest and hands and was taken to the hospital for treatment. His injuries are not life-threatening.

It was unknown early Monday whether the man would face any charges in the incident.