Lisbon, Portugal
 — 

At least three people were killed and several injured by a derailment on a funicular railway in Lisbon, Portugal, on Wednesday.

Emergency teams are at the site, where some people remain trapped, CNN Portugal reported.

A source at the Public Security Police said at least three people had been killed when the derailment occurred and there were about two dozen injured people – at least nine of whom were in a serious condition.

According to CNN Portugal, the Homicide Brigade of the Judiciary Police has been called to investigate the cause of the accident.

The Glória Funicular, which can carry up to 42 people, is a Lisbon landmark and is very popular with tourists visiting the city.

It is more than a century old, having first opened in 1885, according to Lisbon’s official tourism site.

Carris, the public transportation company that manages the funicular, told CNN Portugal that its teams are at the site, and that “all means have been activated” to respond to the accident.

The “priority is to monitor the situation,” an official source said, without giving further details about the possible cause of the derailment.

Portuguese President Marcelo Rebelo de Sousa’s office said in a statement that the president “deeply regrets” the incident and offers his condolences to those affected.

This is a developing story and will be updated.