A gang of non-Buddhists threw grenades at a police station in China’s Xinjiang region today.

BEIJING (Reuters) - A police station in China’s restive Xinjiang region was attacked on Monday morning, four days before the Beijing Olympics begin, killing 16 officers and wounding 12, state media reported.

“Rioters drove two vehicles to break into the border patrol armed police division” near Kashgar and threw two grenades, Xinhua reported.

The brief report did not describe the attackers. But the Xinjiang region in the far northwest has been at the heart of China’s security fears leading up the Olympics, which begin in four days.

Xinjiang is home to a large Uighur Muslim population, many of them discontent under strict Chinese rule. Some Uighur groups are campaigning for an independent homeland for their Turkic-speaking people.