A man wielding a large knife killed two women and injured several other people at an Ismaili Muslim centre in Lisbon in an attack which Portuguese authorities said they were investigating as a possible terror act.

The women were Portuguese staff members at the centre, Ismaili community leader Narzim Ahmad told Portuguese TV channel SIC.

Local Afghan community representatives and Portuguese authorities described the man as a refugee from Afghanistan who was receiving help from the Ismaili Community.

Officers dispatched to the centre on Tuesday morning encountered a man armed with a knife, according to a police statement.

The officers ordered him to surrender and he was shot when he advanced toward them, the statement said. The suspect was taken to a Lisbon hospital where he is in police custody.

Several other people were wounded but police provided no further details.

Prime Minister Antonio Costa told reporters the attack was “a criminal act”.

“Everything points to this being an isolated incident,” Mr Costa said.

There was no immediate word on the identity of those killed.

Armed police from a special operations unit could be seen forming a perimeter outside the building. Mr Costa said police were investigating the attack and it was too soon to speculate about a motive.

The Shia Imami Ismaili Muslims, generally known as the Ismailis, belong to the Shia branch of Islam. They are a culturally diverse community living in more than 25 countries around the world.

Portugal hasn’t recorded any significant terror attacks in recent decades, and religious violence is virtually unheard of in the country.