OAKLAND — A BART train derailed near the 12th Street station in Oakland on Wednesday morning and was evacuated of about 75 people.

No one was reported injured in what BART spokesman Linton Johnson called "a minor derailment." Oakland firefighters responding to the scene treated two people who complained of chest pains and a man who complained of back pain.

A man was found in the station having a seizure shortly after the derailment, but it was unclear whether he had been a passenger on the train.

The five-car, Richmond-bound train derailed about 10:30 a.m. and came to a stop about 200 feet from the station's platform. BART staff members and Oakland firefighters opened the doors and escorted the passengers off the train.

Three of the front four wheels on the train's lead cab were off the tracks after the derailment, but the cause remained unclear and under investigation.

BART police briefly interviewed each passenger of the train to get their name and contact information.

The train remained stuck in the tunnel with no estimate of when it would be moved, but the 12th Street station has three tracks, so most trains were not affected and ran on time. Passengers riding the Fremont-Richmond line were delayed about 10 minutes.

The station was shut down for about 30 minutes.