(updates injury figure, adds details)
At least three people were killed and 155 others injured when two trains collided Thursday morning outside Argentina's capital, officials said.
The accident occurred in Castelar, located 30 kilometers (about 19 miles) west of Buenos Aires, at 7:07 a.m. when a train headed for the city of Moron hit an empty train that was stopped on the tracks.
The cause of the accident has not been determined, officials said.
Dozens of people have signed up on a registry set up by officials for those trying to find loved ones.
Patricia Mazziaco, a Bolivian citizen, said she was looking for her uncle.
"We are looking for him, we have not been able to contact him," Mazziaco told Efe, adding that one of her cousins was killed in last year's train crash at the Once station.
"There are three dead," railway union official Ruben Sobrero told C5N television.
"There are fatalities," Moron Mayor Lucas Ghi confirmed.
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 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 at the Once station in Buenos Aires. EFE