Family of suicide bombers hits police headquarters in Indonesia

May 14 (UPI) -- A family of five riding motorbikes carried out a suicide attack on a police headquarters in Indonesia Monday, one day after another family attacked a church.

Police said four bombers on two motorbikes drove into the main gateway of the police building in Surabaya. All four attackers died, but an 8-year-old girl on one of the motorbikes survived.

Ten people were injured in Monday's attack in Indonesia's second-largest city; four were police officers.

Another family of suicide bombers attacked three Christian churches Sunday, killing seven worshipers and security personnel.

All six family members died in the bombings, including two children, police said. The Islamic State took responsibility for the attacks.

Indonesia has seen a rise in Islamist militancy in recent months as IS fighters have been defeated across Syria and Iraq.

No group immediately took responsibility for Monday's attack.

Another bomb exploded Sunday night at an apartment and killed three members of a family who police said may have been planning an attack. Pipe bombs were found.

National Police Chief Gen. Tito Karnavian said the terrorists behind the church attacks used an explosive called triacetone triperoxide, sometimes referred to as "Mother of Satan."

Karnavian said the explosives are made from widely available materials.

"All of those materials are very dangerous since they can easily trigger an explosion at random because of their sensitivity," the police chief said during a press conference.

Indonesia's President Joko Widodo called the series of attacks "cowardly" and "barbaric."

"I have ordered the chief of police to take firm steps, there is no compromise in taking actions on the ground to stop terrorist acts," Widodo wrote on Twitter.

More than 82 percent of Indonesia's roughly 261 million people are Muslim. Almost 10 percent of the population is Christian.