(CNN) Two Mexico City subway trains crashed on Monday, injuring some passengers.

The trains crashed at the Oceanía metro station , Mexico City Mayor Miguel Ángel Mancera said in a Twitter post.

"There are injuries, but we do not have people who lost their lives," Mexico City Fire Chief Raúl Esquivel told CNN affiliate FOROtv

Security officials in Mexico City said emergency workers were at the station. A tweet from FOROtv showed the trains jammed into each other, with one train apparently pushed up off the tracks.

Confirma @SSP_CDMX que servicios de emergencia continúan laborando en el Metro Oceanía tras choque de trenes pic.twitter.com/PdQbitttEL — FOROtv (@Foro_TV) May 5, 2015

At least 12 people were injured, none of them seriously, a post on the metro's official Twitter account said . Three of them were transported to hospitals.

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