At least 17 people killed and 22 others injured after streetcar derails in Lisbon

At least 17 people have been killed after a funicular tram derailed in the Portuguese capital Lisbon derailed on Wednesday.

Portuguese officials say the electric streetcar, which violently crashed into a building, also injured 22 others, with four of them having been transferred to the city's main hospitals to receive treatment for critical injuries.

The nationalities of those killed and injured is not yet clear, but authorities suspect foreign nationals were among the casualties, seeing as the iconic tram is a popular tourist attraction.

Portugal's President Marcelo Rebelo de Sousa offered his condolences to those affected by the incident.

The yellow-and-white streetcar, which travels up and down a steep city hill, was lying on its side on the narrow road that it travels along, Portuguese television showed.

Its sides and top were partially crumpled. Several dozen emergency workers were at the scene responding to the tragic accident on Wednesday.

The cause of the accident was not immediately known, but officials suspect it was probably due to a broken cable. The crash reportedly occurred at the start of the evening rush hour, at around 6 pm local time.

Authorities say an investigation has been launched to uncover the cause behind the fatal accident.

The funicular, known as Glória, can carry more than 40 people, seated and standing. It is commonly used by Lisbon residents and tourists alike, and is widely seen as one of the city's icons.