At least three people were killed and more than 50 others injured when two trains collided Thursday outside Argentina's capital, union and government officials said.

"There are three dead," railway union official Ruben Sobrero told C5N television.

"There are fatalities," Moron Mayor Lucas Ghi said, without providing any figures.

Emergency services personnel are working to rescue people trapped in the wreckage.

The majority of the injured sustained bruises, fractures and cuts, medical personnel told reporters.

The accident occurred in Castelar, located 30 kilometers (about 19 miles) west of Buenos Aires, just after 7:00 a.m. when an empty train was rear-ended by another train.

The Sarmiento line, where the accident happened, is the same one on which 51 people were killed and more than 600 others injured in an accident in February 2011. EFE