JAKARTA, Indonesia 

At least 20 people were injured in a suicide attack targeting a Catholic church on Indonesia’s South Sulawesi Island on Sunday, police said.

The incident took place outside the church in the city of Makassar at 10.28 a.m. local time (0328GMT) during a service, said police spokesperson Endra Zulpan.

According to National Police spokesperson Gen. Argo Yuwono, two alleged suicide bombers arrived on a motorbike and tried entering the church.

A destroyed motorbike and body parts were found at the scene and police said the two attackers had died. The blast happened by the church's side entrance.

While the injured have been shifted to hospitals, there has been no claim of responsibility for the attack so far.

Indonesian President Joko Widodo condemned the attack, calling it a "terrorist act," and urged people to remain calm.

“We will ensure that everybody can worship freely, without fear,” said the president during a virtual press conference.

He directed the police to conduct a thorough investigation into the incident, arrest the perpetrators and uncover the terrorism network’s origin.

Urging the public not to rely on information from unofficial sources, Mohammad Ramdhan Pomanto, the mayor of the Makassar city, said security in the region has been increased and an investigation is underway.

Indonesia is the world's biggest Muslim-majority nation. In May 2018, at least 13 people were killed in multiple suicide bombings at three churches in Surabaya, the country's second-largest city.