LISBON, Portugal (AP) — A 12-year-old boy stabbed and injured six other children Tuesday at a school in Portugal, police said.

One child was seriously injured and the five other victims suffered light wounds in the attack at a school in Azambuja near Lisbon, Portuguese national police said. The victims were from 11 to 14 years old.

The attacker was in custody, the police said.

Portuguese Prime Minister Luís Montenegro condemned the attack and wished for the quick recovery of the injured children in a message posted on social media platform X. He called it an “isolated attack” that was extremely rare in his country.

“It was an isolated act and a strange occurrence in Portuguese society, but one that should make everyone who works in public space reflect with a sense of responsibility,” Montenegro wrote in Portuguese.