A subway train derailed Sunday near downtown Washington, sending 16 people to the hospital and prompting the rescue of 60 people from a tunnel, officials said.

The accident happened at about 3:45 p.m. near the underground Mount Vernon Square station, Metro spokeswoman Cathy Asato said. There were about 150 people on the train.

At least one person had a serious but not life-threatening injury, Asato said. The other injuries were mostly "bumps and bruises."

It took about 45 minutes to get everyone off the six-car train, she said. There was no fire.

Passengers in the first four cars were able to escape to the station the train had been pulling into, Asato said. Passengers in the fifth car, which had derailed, and the sixth were escorted by rescue personnel along a catwalk into a station.

The cause of the derailment was being investigated.

Witnesses said people started to panic when the six-car train began shaking, and some passengers began running to the back of the train.

"I was in a cab that actually shattered — the front part of it — those windows in between the two cars," said rider Lauren Sprigg.

Service on two lines was halted in both directions around the station, and Asato said a temporary shuttle bus would take passengers around the accident scene.