According to authorities, a man who was responsible for an attack that left 20 dead and more injured in February in Yechang, Xinjiang, has been sentenced to death. Reports say that the attack was led by a “terrorist” group. The Associated Press reports:

The man’s name — Abudukeremu Mamuti in Chinese — suggested he was from the mainly Muslim Uighur minority that populates the northwestern region and has long complained of political and religious oppression under Chinese rule.

According to a statement posted on an official Xinjiang judicial website, the defendant started preaching “religious extremism” last year and recruited people to form a “terrorist group”.

Then on February 28, he gathered all members at his home, armed them with knives and hatchets and took them to the market in Yecheng town — which belongs to the wider Kashgar prefecture — the statement said late Monday.

There, they killed 13 people on the spot and injured 16 others — two of whom later died of their injuries. Mamuti was detained on the scene and seven other attackers were shot dead. One other suspect also later died.

Since 2009, security has been high in the region due to ethnic tensions between Uighur and Han communities. Reuters reports on the location of Xinjiang in a region where China, India and Pakistan all have strategic interests:

China is extremely sensitive to Western suggestions that it mistreats or puts restrictions on Uighurs. Beijing often blames what it calls violent separatist groups in Xinjiang for attacks on police or other government targets, saying they work with al Qaeda or militants in ex-Soviet Central Asia to bring about an independent state called East Turkestan.

Some Chinese officials have also blamed attacks on Muslim militants trained in Pakistan. Yecheng, also known by its Uighur name of Kargilik, is close to the disputed region of Kashmir, ruled in part by India and Pakistan.

But exiled Uighur groups and human rights activists say China overstates the threat posed by militants in Xinjiang.

The Chinese foreign ministry said the Yecheng incident should not be overblown and that it firmly opposes “a small group of violent terrorists and separatists destroying” the region’s peaceful development.

According to the BBC, China is blaming groups that are linked to al-Qaeda for the violence, but exiled Muslim Uighur community and human rights activists claim that this is an overstatement of the threats in Xinjiang.