Attackers wielding knives burst into a child’s birthday party in central Mexico, stabbing and slashing to death 11 people, including two minors, authorities have said.

Hidalgo state prosecutor Javier Ramiro Lara Salinas said at a news conference that the preliminary investigation suggested the attack in a house near Tizayuca, just north of Mexico City, was a “settling of scores.”

Among the victims was a man with an ID identifying him as a Mexico City police officer. Lara said the home’s owner had served time on a kidnapping charge in Mexico State.

Authorities received a 911 call after midnight yesterday alerting them to the killings.

Officers discovered 11 bodies seven of them female and four male, with two minors, state authorities said. They had initially said the victims were seven men and four women. Four minors survived the attack without injuries.

None of the victims was. All were killed by knives or other cutting weapons. The area had largely been spared the violence affecting other parts of Mexico.