The Islamic State group has claimed the church bombings in Indonesia, which killed at least 13 people on Sunday. Forty-one people, including two police officers, were hospitalized with injuries, police spokesman Frans Barung Mangera said. A family of six have been blamed for the attacks which were carried out in quick succession across three locations.

The Indonesian police say the parents including their four children had been to Syria and had been radicalised by the Islamic State.  The BBC reported that Indonesian 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 Java Island but provided no proof to substantiate its claim. Authorities have not confirmed the claim.

Authorities said the parents used their children, girls aged 9 and 12 for the bombing of the Indonesian Christian Church in the city of Surbaya. The father then drove to Pentecost Central Church, where he detonated the bomb in his vehicle. Around the same time, the two sons aged 16 and 18 drove motorcycles to Santa Maria Catholic Church, where they, too, detonated bombs. All the bombings carried out were suicide attacks which killed all six of the family members.

Indonesia is the world’s most populous muslim country where over 82% of the population follows Islam. Indonesia has long struggled with domestic terrorist groups, particularly the al-Qaeda affiliated group Jemaah Islamiyah, which claimed responsibility for 11 attacks between 2000 and 2010, including the deadly 2002 Bali bombings that left more than 200 people dead and hundreds injured, many of them tourists. In recent years, Indonesia has been confronting ISIS attempts to recruit members in the country.

The use of children to execute Sunday’s attacks in Surabaya, a port city on Java island, has sent shockwaves across the sprawling country.

The Southeast Asian terror network responsible for the Bali attacks was obliterated by a sustained crackdown on militants by Indonesia’s counterterrorism police with U.S. and Australian support. A new threat has emerged in the past several years, inspired by IS attacks abroad. Experts on militant networks have warned for several years that the estimated 1,100 Indonesians who traveled to Syria to join IS posed a threat if they returned to Indonesia.

Karnavian named the father as Dita Futrianto and said he was head of the Surabaya cell of Jemaah Anshorut Daulah, an Indonesian militant network affiliated with IS that has been implicated in a number of attacks inside Indonesia over the past year. He identified the mother as Puji Kuswati.

President Joko “Jokowi” Widodo visited the scenes of the attacks and described them as “cowardly actions” that were “very barbaric and beyond the limit of humanity.”

The church attacks came days after police ended a hostage-taking ordeal by imprisoned Islamic militants at a detention center near Jakarta in which six officers and three inmates died. IS has claimed responsibility for that attack as well.

(The above story first appeared on LatestLY on May 14, 2018 05:54 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).