Jakarta – Security forces fired warning shots when hundreds of students demanding a share of oil earnings stormed a Caltex Indonesia housing complex on Sumatra island Tuesday, wrecking cars and smashing office windows, sources said.

Students from the local Riau University and the Institute of Islamic Studies damaged almost 30 cars along with a club and a hotel in the complex and smashed office windows with rocks, one source said.

"Students from universities in Riau protested to demand a 10 percent share of oil revenues," Budi Arief, the telephone operator at the Caltex complex, told AFP by phone from Rumbai.

Rumbai is on the outskirts of Pekanbaru, the capital of Riau province, on Sumatra island.

Caltex public relations officials were not immediately available for comment. But spokesmen have said the company contract provides for much of the 80 percent share of the oil it gives to Jakarta to go to the province. Caltex produces almost half of Indonesia's 1.5 million barrels of crude oil a day.

A resident said they had been warned of the protest. "The students came at about 11.30am ... it was a planned event and there had been news that they were going to protest. But ... it was pretty scary."

A nurse at the Caltex hospital said nine protestors were admitted. She said they had been beaten by the police but their injuries were not serious.

Parliament is debating a bill on revenue sharing with the provinces, but it has come in for sharp criticism from economists who warn that more concessions must be made.