Image copyright Reuters Image caption Three of the defendants were handed death sentences

Fifty-five people have been sentenced for terrorism, separatism and murder at a stadium in China's north-western Xinjiang region, state media report.

The defendants, who appeared to be from the region's Muslim Uighur community, were presented at a venue holding about 7,000 spectators.

Three of the defendants were sentenced to death.

Chinese officials have blamed militant Uighur groups for a growing number of violent attacks across the country.

Photos from the open-air mass sentencing showed police trucks parked near a running track.

Prisoners wearing orange vests stood in the back of the vehicles, surrounded by armed guards, their heads bowed.

Image copyright Reuters Image caption State media said that local officials and residents were among those who watched the proceedings

Image copyright Reuters Image caption There were few details released about the cases of those on trial

The sentencing happened in Yili, near China's border with Kazakhstan.

Local officials and residents watched the proceedings.

Those sentenced to death had used weapons to murder a family last year "using extremely cruel methods", according to reports.

Celia Hatton, BBC News, Beijing

This kind of mass sentencing is reminiscent of China's Cultural Revolution in the 1960s and 1970s, when large groups of people would gather to denounce those who crossed the Communist Party leadership. In the 1980s and 1990s, public trials were also used during the government's widespread attempts to crack down on crime.

Startled by an increasing number of bloody attacks on civilians linked to militants within Xinjiang's ethnic Uighur community, the Chinese government is returning to this type of political theatre.

Beijing is attempting to calm the wider Chinese public, by showing a blatant display of force, while also issuing a warning to Uighurs hoping to challenge the dominance of the minority Han Chinese moving into Xinjiang.

No further details about the defendants' cases were immediately available.

The public rally seems to have been a show of force by the Chinese government, which has just launched a national anti-terrorism operation focusing on Xinjiang.

Officials last week announced a one-year campaign against militant violence in Xinjiang, banning people from conducting or supporting extremist activity.

Uighurs and Xinjiang

Uighurs are ethnically Turkic Muslims

They make up about 45% of the region's population; 40% are Han Chinese

China re-established control of the region in 1949 after crushing the short-lived state of East Turkestan

Since then, there has been large-scale immigration of Han Chinese

Uighurs fear erosion of their traditional culture

Why is there tension between China and the Uighurs?

The announcement came after 39 people were killed last week when five suicide bombers attacked a street market in Urumqi, Xinjiang's capital.

Beijing has blamed this - and other recent mass-casualty attacks - on Uighur separatists.

These include an attack in Beijing, where a car ploughed into pedestrians in Tiananmen Square, killing five people, and attacks at railway stations in Urumqi and Kunming.

China says it is pouring money into the Xinjiang region, but some Uighurs say their traditions and freedoms are being crushed.