An off-duty Los Angeles Police Department officer died Thursday evening and three other people were injured in a vehicle collision in Diamond Bar, authorities said.

The accident occurred about 5:30 p.m.on Grand Avenue near Longview Drive. The officer's car apparently hit at least one oncoming vehicle, the Los Angeles County Sheriff's Department said.

The three injured people were taken to hospitals. Their condition was not immediately known.

The name of the officer was not released. The cause of the accident was under investigation.

[Updated 10:03 p.m.: The officer was a female, and one of the vehicles overturned several times in the chain-reaction collision, said Steve Whitmore, Sheriff's Department spokesman.]