At least three people have been killed and 20 others injured after Lisbon's famous Gloria funicular cable railway derailed and crashed, emergency services said.

The head of Portugal's Civil Protection Authority said that several people remained trapped at the scene and nine people were in a serious condition.

Footage shared widely on social media showed the yellow funicular overturned and almost entirely destroyed. People could be seen fleeing the area on foot as what appears to be smoke filled the air.

Portuguese President Marcelo Rebelo de Sousa has issued a statement expressing his "sympathy and solidarity with the families affected by this tragedy".

It is unclear how many people were on board at the time of the crash, which occurred near the Avenida da Liberdade around 18:05 on Wednesday evening.