Daesh claimed responsibility for suicide attacks on worshippers during Sunday services in three churches in Surabaya. Police say all the attackers, including a woman with children, were members of one family.
Suicide bombers on motorcycles and including a woman with children targeted Sunday Mass congregations in three churches in Indonesia's second largest city, killing at least 13 people and wounding dozens in one of the worst attacks on the Christian minority, police said.
The first attack struck a Sunday Mass at the Santa Maria Roman Catholic Church.
Mangera said two police officers were among a total of 41 wounded.
The blast was followed by a second explosion minutes later at the Christian Church of Diponegoro and a third at the city's Pentecostal Church, Mangera said.
At least one of the attackers was killed when they detonated their bomb at Santa Maria. It was not clear if any other perpetrators were among those killed or injured.
TRT World's Arabella Munro reports.
Suicide bombers from one family
Indonesia's national police chief says all the suicide bombers were members of one family, including children and teens.
The national police chief, Tito Karnavian, said the family had been in Syria, where Daesh until recently controlled a large swath of territory.
He said the family's father exploded a car bomb, two sons aged 18 and 16 used a motorbike in their attack and the mother was with two children aged 12 and 9.
Daesh claim responsibility
Daesh claimed responsibility for the attacks on its Amaq news agency, without providing any evidence.
Earlier, a spokesman for Indonesia's intelligence agency said the Sunday's attacks were suspected to be carried out by the Daesh-inspired group Jemaah Ansharut Daulah (JAD).
Wawan Purwanto, communication director at the agency, also told Metro TV that the attacks were likely to be linked to a deadly prison hostage incident at a jail near Jakarta involving militants last week.
Asked who he thought were the brains behind the attacks, Purwano said: "Still the old group, JAD, who has planned this for sometime."
In Jakarta, Indonesia's capital, the Indonesian Church Association strongly condemned the attacks and called on people to wait for authorities to investigate.
"We are angry with these attacks, but we leave it to the authorities to resolve them," said Gormar Gultom, an official with the association.
Two of Indonesia's largest Muslim organizations, Nahdlatul Ulama and Muhammadiyah, also condemned the attacks.
Worst attack since 2000
The bombings were the worst since a series of attacks on churches on Christmas Eve in 2000 killed 15 people and wounded nearly 100. Religious minorities, especially Christians, have been repeatedly targeted by militants.
The latest attacks in predominantly Muslim Indonesia came days after police ended a riot and hostage-taking at a detention centre near Jakarta that left five dead and five injured. The Daesh terror group had claimed responsibility.
Indonesia has carried out a sustained crackdown on militants since bombings by Al Qaeda-affiliated radicals in Bali in 2002 killed 202 people.