LOS ANGELES, June 3 (Xinhua) -- A suspect was killed and all hostages were freed early Wednesday after an hours-long standoff at a bank in Bakersfield, U.S. California, authorities said.

"The hostage situation concluded following an officer-involved shooting involving Federal Bureau of Investigation personnel," the Bakersfield Police Department said in a news release.

The suspect was pronounced dead and all hostages were freed unharmed and received medical evaluation and treatment, police said, adding that the hostage situation ended at around 4:20 a.m. Wednesday.

The standoff began at about 1 p.m. Tuesday after Bakersfield police responded to a reported bomb threat at a Chase Bank in the city, located about 180 km north of Los Angeles. Several buildings in downtown Bakersfield, including the city hall and the local police headquarters, were locked down due to the threat.

Authorities have not disclosed the suspect's identity or motive as the investigation continues. ■