URUMQI - A total of 37 civilians were killed and another 13 injured in a terrorist attack Monday in Shache County, Kashgar Prefecture, northwest China's Xinjiang Uygur Autonomous Region, authorities said Sunday.

Police gunned down 59 terrorists and arrested 215 others, the regional government said after a meeting Saturday presided by Zhang Chunxian, secretary of the regional committee of the Communist Party of China.

The case was first reported Tuesday, but no figures were given except that dozens of people died.

Special: Crackdown on Terrorism

Among the dead were 35 Hans and two Uygurs, the government said.

Out of the 31 vehicles smashed in the violent attack, 6 were burnt.

Police confiscated long knives, axes as well as the terrorists' banners that hailed "holy war."

A gang armed with knives and axes attacked a police station and government offices in Elixku Township early Monday morning, and some moved on to the nearby Huangdi Township, attacking civilians and smashing vehicles as they passed.

The gangsters also set roadblocks on the Bachu-Shache Road and stopped vehicles passing by, before slashing passengers indiscriminately and forcing civilians to join them in the terror attack, according to police.

Investigations showed that it was an attack jointly "organized and premeditated" by terrorists both in and outside China, the government said.

The mastermind behind the attack was identified as Nuramat Sawut from Elixku Township, who had close connections with the terrorist organization East Turkestan Islamic Movement (ETIM).

Sawut had been spreading separatism and religious extremism with audio and video materials since 2013. Through this process he developed a terrorist group and became its leader.

Since the beginning of the Islamic holy month of Ramadan, the group had had multiple gatherings in remote places, during which they made attack plans and prepared tools for their violent acts.

Zhang Chunxian said that the terrorists will be punished in accordance with law, and that anyone committing crimes must be brought to justice.

On Friday, police shot dead nine suspected terrorists and captured another in Hotan Prefecture, two days after extremists murdered the imam of China's largest mosque, Jume Tahir, in Xinjiang.

Shache witnessed another terror attack on December 30, 2013 when nine knife-wielding terrorists attacked a police station. They threw explosives and set police cars on fire. Police shot dead eight terrorists.

On May 22, an attack on a market in Urumqi, the regional capital, left 31 dead and 94 injured.