Jakarta (CNN) Police believe a husband, wife and their four children carried out the suicide attacks on three churches in Surabaya that left seven people dead, Indonesia's top cop said Sunday. The attackers included two daughters aged 9 and 12 years old, said Head Gen. Tito Karnavian, the country's highest-ranking police official. Earlier reports indicated at least 10 people died in the Sunday morning attacks, but Karnavian said during a news conference that seven victims were killed. Forty-one people, including two police officers, were hospitalized with injuries, police spokesman Frans Barung Mangera said previously. The six bombers also died, Karnavian said. Investigators believe the parents belong to Jamaah Ansharut Daulah, a terrorist group that lends its support to ISIS in Indonesia, the police general said. Through its Amaq News Agency, ISIS claimed responsibility for what it called "martyrdom attacks" in the port city on the east coast of Ja