URUMQI - Police in northwest China's Xinjiang Uygur autonomous region on Sunday revealed details of a terrorist attack that took place on Friday, involving 13 terrorist suspects.

Police investigation showed that the attack in the seat of Wushi county were "organized, premeditated terrorist attacks," said an official statement.

Eight terrorists were killed by police and three others by their own suicide devices during the attack.

According to the police, a man named Mehmut Tohti started to spread religious extremism three years ago. He headed a group of 13 terrorist suspects since September 2013.

The terrorists, riding motorbikes and cars, carried explosive devices and knives and attacked a team of police on patrol at around 4 p.m. on Friday, according to the police.

Police seized dozens of explosive devices and hacking knives at the scene.