The attack took place at the Ismaili Centre. The suspect, who was in possession of a large knife, is reportedly of Afghan origin, reports BBC.

According to reports, the police detained the attacker later.

Portuguese Prime Minister Antonio Costa said it appeared to be "an isolated act" and discussing a possible motive was "premature", reports BBC.

The Ismaili Centres are symbolic markers of the permanent presence of the Nizari Ismailis in the countries and regions in which they are established, characterised by the Aga Khan IV as 'ambassadorial buildings'.