Two women were stabbed to death in an Ismaili Muslim Center in Lisbon, Portugal, on Tuesday. Police shot and injured the man suspected of attacking the women.

According to The Associated Press, the women were Portuguese staff members in the center. When police were called to the center, they were met with the suspect carrying a large knife. After the officers asked him to surrender, the suspect advanced toward them, and police shot him.

“The perimeter of the building has been secured and the Ismaili community is co-operating fully with a police investigation,” a statement on the Ismaili website said, per BBC.

Prime Minister Antonio Costa said, “Everything points to this being an isolated incident,” in a statement on the Ismaili website.

If the incident is deemed to be a terror attack, it would be the first significant terror attack to take place in Portugal including any acts of religious violence in decades, per AP.

Shia Imami Ismaili Muslims “belong to the Shia branch of Islam,” and Ismaili Muslims live in communities in more than 25 countries across the world, according to AP.

This is a developing story and will be updated with new information.