BUENOS AIRES (CNN) -- At least 49 people were killed and more than 600 people were injured when a train plowed into a platform at a Buenos Aires station Wednesday, state media said.
Emergency services director Alberto Crescenti said the number of casualties could increase, according to the state-run Telam news agency.
Transportation Secretary Juan Pablo Schiavi called the crash "very serious."
Authorities believe there were problems with the train's brakes, Schiavi said.
The packed train was traveling at 26 kilometers per hour (16 mph) when it crashed, he said.
Shaken passengers told reporters that the crash sounded like a bomb blast.
"We all fell to the ground. It was horrible," one woman said.
(CNN)