Authorities in Northern California said that a man died Tuesday after exploding a pipe bomb outside a health clinic.

The Alameda County Sheriff’s Office confirmed a report of an explosion at the San Antonio Neighborhood Health Center in Oakland, according to CBS San Francisco. Deputies said that the blast was reported at around 6:30 p.m.

A source told KTVU that a man in a wheelchair rolled up to the clinic and exploded a pipe bomb. Authorities were searching for secondary devices. Police were investigating the death as a suicide.

The man wasn't immediately identified.

CBS San Francisco reported that the Alameda County Sheriff’s Office was assisting the Oakland Police Department in the investigation.

Click for more form CBS San Francisco.