Nine people taken to hospitals after problems with BART train in Oakland.

At least nine people were taken to the hospital Wednesday after a San Francisco Bay Area Rapid Transit train’s emergency brakes malfunctioned, stranding hundreds of passengers in a tunnel, officials said.

Oakland Fire Battalion Chief Melinda Drayton said the nine were among 11 passengers who were treated for medical issues. The extent of their injuries was not clear, but Drayton said many of the passengers complained of respiratory problems caused by brake dust.

One passenger was found in a semiconscious state and another suffered an asthma attack.

The San Francisco-bound train stopped around 8:15 a.m. in the Berkeley Hills between BART’s Orinda and Rockridge stations when the train’s emergency brakes became “spontaneously engaged,” a BART spokeswoman said.

A technician was able to release the broken brake around 9:30 a.m., and the disabled train moved on its own power to the Rockridge station, where about 700 passengers onboard were evacuated with fire and medical crews waiting, a BART spokeswoman said.

The incident created significant delays on the line as the two stations were shut down. Full service was restored by noon with delays up to 15 minutes, BART spokesman Jim Allison said.