A firebomb attack outside a church in Indonesia's East Kalimantan province has wounded four children.

A Molotov cocktail was thrown at the carpark of the Oikumene Church in the city of Samarinda.

The four children were slightly wounded and taken to hospital for treatment.

National police spokesman Brigadier-General Agus Riyanto said a number of vehicles were also damaged.

A suspect has been arrested and is being questioned by police.

Tensions have been high in Indonesia, with large Muslim crowds protesting against Jakarta's Christian Governor — known as Ahok — who they accuse of blasphemy.