China will try eight people linked to a car-bomb attack in Beijing's Tiananmen Square last year, prosecutors said, as the government escalates a crackdown on violence emanating from its restive Xinjiang region.

Three ethnic Uighurs from the western region drove a car loaded with petrol canisters into the gate of the Forbidden City in October, an attack that left two dead, besides the three people in the car, and 40 injured.

In a statement released Friday, Xinjiang prosecutors said eight people were suspected of organising, leading and participating in crimes of a terrorist organisation, as well as endangering public safety.

A court in Urumqi, the regional capital, would try the case, the statement said, but gave no date. The names of the suspects were not released.

Xinjiang is home to Muslim Uighurs, some who are seeking an independent state.

Authorities in Xinjiang just days ago announced a mass sentencing in a stadium for 55 people on offences including terrorism, state media said, as they press a crackdown on escalating violence.

Beijing has vowed a year-long crackdown on terrorism following a string of attacks blamed on militants from Xinjiang.

Last week, five suspects killed 39 people and wounded more than 90 in a car and bomb assault on a market in Urumqi.

On April 30, the final day of a visit by Chinese President Xi Jinping to the region, attackers armed with knives and explosives killed one person and wounded 79 at an Urumqi railway station.

And in March, knifemen killed 29 people and wounded 143 at a railway station in the southwestern city of Kunming, an incident dubbed "China's 9/11" by state media.

Analysts question how organised the groups carrying out the attacks are, while rights groups point to repression of Uighurs and economic favouritism towards an influx of Han Chinese, the country's ethnic majority, into the resource-rich region.