Sabotage is suspected to be behind four recent explosions at a granite quarry in Karimun on Indonesia's Riau Islands.

No one was injured in the blasts which happened in the early hours of Friday at PT Karimun Granite, a subsidiary of Singapore-based Hong Leong Asia.

The Head of Police for Riau District, Brigadier-General Sutarman, said that three of the blasts affected the conveyor belt system used for transporting the granite to the port.

The fourth happened near the guard house.

Foul play was suspected, added the police chief.

Brigadier-General Sutarman was quoted as saying this in the Indonesian newspaper, KOMPAS.

A team of forensic specialists from Medan have been flown to Karimun to investigate the blasts.

The export of granite from Indonesia has been very much in the news in the past few weeks, with Indonesian leaders saying a ban is being considered for environmental reasons.

Indonesia is a major exporter of granite to Singapore. - CNA/ir