Los Angeles police responded to a radio call of a suspicious package on a Metro bus near Wilshire and Crescent Heights boulevards at about 10:30 a.m.
A person yelled that a passenger on the bus had a bomb and ran out, police said.
The bus was evacuated and the street was closed between Fairfax and La Jolla avenues as authorities investigated.
Shortly after 12:30 p.m., police said they found no evidence of an explosive device, and Wilshire Boulevard was back open.