JAKARTA: An explosion outside a church on Borneo island wounded several children on Sunday, Indonesian police said.

Several vehicles were also damaged in the explosion in the parking lot of the Oikumene Church in Samarinda, the provincial capital of East Kalimantan province, said national police spokesman Brig General Agus Riyanto. He did not give more details and said the incident was being investigated.

Media reports cited local police spokesman Lt Col Fajar Setiawan as saying the explosion came from a Molotov cocktail thrown by a man riding on a motorbike.

Setiawan said the man was arrested, while four children were slightly wounded and were being treated at a hospital.

It was the second explosion at a church in Indonesia this year. In August, a would-be suicide bomber failed to detonate a bomb during a Sunday Mass in a church in Medan, the provincial capital of North Sumatra in western Indonesia, but he managed to injure a priest with an axe before being restrained.

Indonesia, the world's most populous Muslim nation, has carried out a sustained crackdown on militant networks since the 2002 Bali bombings that killed 202 people.