Australian police were called to an immigration detention center on remote Christmas Island early Wednesday to put down a violent protest by detainees.

About 50 detainees lit fires and threatened police with makeshift weapons. Some detainees climbed onto the roof of the center, located more than 2,000 kilometers from the Australian mainland.

A spokesman for the Australian Federal Police says police used tear gas, “bean bag” cushion bullets and “sound and flash distraction” devices to control the situation.

Australia's immigration detention centers are crammed with refugees from countries such as Afghanistan, Sri Lanka and Iraq, most of whom arrive by boat through neighboring countries such as Indonesia. Under Australian law, anyone arriving without proper documentation is detained while their application for asylum is considered, a process that often takes months.

Riots broke out earlier this year at Christmas Island and at Sydney's Villawood Detention Center, where at least 100 detainees set fire to several buildings in April.

The government has proposed new rules that will place tougher restrictions on refugees who commit offenses while in detention. Asylum seekers who fail so-called “character tests” would be barred from receiving permanent residence in Australia, and could face deportationor be granted temporary visas.