About 500 passengers were traveling in the train's eight cars, and all train signals were working at the time of the crash, said train company spokesman Sukendar Mulya.
Two train cars derailed, including a women-only carriage, and hundreds of panicked passengers ran away, many screaming and crying. Rescuers pulled out three bodies pinned under the wreckage, said Sukarno, a firefighter. The cause of the accident is being investigated.
"My position was near the door, but I could not move because I was ... trampled by other passengers," Veronica, a commuter from the derailed women-only car who uses only one name told MetroTV. "We managed to escape after people from outside broke the windows. I saw many victims with burns on their legs, hands and stomachs."
She said that the carriage quickly filled with thick smoke, making it difficult to breathe.
The accident occurred near the site of a collision between two trains in 1987 that killed 156 people and injured hundreds more.
Commuter trains are often packed with passengers due to the lack of other forms of public transportation in Jakarta, which has some of the worst traffic jams in Asia.
___
Associated Press writers Niniek Karmini and Ali Kotarumalos contributed to this report.