A suicide bombing outside a church after Palm Sunday Service on the Indonesian island of Sulawesi has injured more than a dozen churchgoers, some seriously.

The blast took place Sunday morning outside the Sacred Heart of Jesus Cathedral in Makassar, capital of South Sulawesi province, as worshipers were leaving the church at the start of Holy Week. Palm Sunday, the first day of Holy Week, commemorates Jesus’s triumphal entry into Jerusalem days before his passion and crucifixion.

Two perpetrators are said to be responsible for the explosion, both of whom died. Inspector General Argo Yuwono, spokesman for the national police, said the injured suffered from wounds around their necks, chests, and legs, adding that some had blisters on their hands and feet.

The congregation had been inside the church at the time of the explosion, according to South Sulawesi police spokesman E. Zulpan.

“We see that there are victims and parts of human bodies have been torn apart. We do not know yet whether they are from the perpetrator or from the people who were close by,” Zulpan said.

Father Wilhelmus Tulak, the church leader who celebrated the Mass, said that that a suspected bomber arrived on a motorbike and attempted to enter the cathedral but was turned away by security guards. The explosion occurred around 10:30am local time.

Makassar Mayor Danny Pomanto said the explosion could have caused far more casualties if it had taken place at the church’s main entrance instead of a side door.