Chinese police said "terrorist attacks" were responsible for the latest wave of violence to hit the restive Xinjiang region in which 12 people were killed, state media reported Monday.

Six people died in explosions -- including blasts in a hairdressing salon and market -- while another six were shot dead by police in Xinhe in Aksu prefecture in China's far west on Friday.

A police investigation has shown the explosions were "organized, premeditated terrorist attacks," the official Xinhua news agency said, as authorities revealed new details of the incident.

"The group rode on three motorcycles to set up explosions at a hair salon and a vegetable market at about 6:40 pm on Friday.

"Shortly after the explosions, the police responded and opened fire to fight back attacks by the group when they were making arrests," the agency reported, adding that six suspects were gunned down and six others died in explosions they set off by themselves.

One policeman was slightly injured but "no bystander casualties" were reported during the arrests, it said.

Located in China's extreme west, along the border with Kyrgyzstan, Xinhe is populated predominantly by members of the country's Uighur minority.

Police have named one suspect who "organized illegal religious activities and spread religious extremism since May last year" and "headed a group of 17 terrorist suspects to make explosives in a rented house," Xinhua said.

The vast Xinjiang region has for years been hit by sporadic unrest by predominantly Muslim Uighurs, which rights groups say is driven by cultural oppression, intrusive security measures and immigration by Han Chinese.

In recent months, it has seen more regular violent incidents, usually involving men armed with knives and explosives, according to official media.

Beijing attributes the unrest to religious extremists and separatism.

The most serious recent violent incident took place in the Turpan area of Xinjiang, leaving at least 35 people dead in June.

China police accuse Uighur academic of 'separatist activites': Xinhua
Beijing (AFP) Jan 25, 2014 - Police in China's western Xinjiang region have accused a prominent Uighur academic detained since last week of being involved in "separatist activities", state media reported Sunday.

Ilham Tohti, an economist who teaches at the Central University for Nationalities in Beijing, has vocally criticised the Chinese government's policy towards his mostly Muslim Uighur minority.

The academic and his mother were taken on Wednesday 15 to an unknown location by several dozen police who seized their mobile phones and computers, his wife Guzaili Nu'er previously told AFP. The mother was released the following day.

Early on Sunday the official Xinhua news agency reported that police authorities in Xinjiang said Tohti "formed a separatist group" and "severely damaged the national security and social stability".

"Ilham Tohti organized a group with the disguise of his identity, colluded with leaders of overseas East Turkistan separatist forces, and sent followers overseas to engage in separatist activities," Xinhua said citing a statement from the municipal public security bureau in the Xinjiang regional capital Urumqi.

Last week, China's foreign ministry said Tohti had been "criminally detained" because he was "under suspicion of committing crimes and violating the law".

The academic has been detained on a number of occasions in the past few years, including for more than a week in 2009 after his website Uighurbiz.net -- an information site on Xinjiang in Chinese and Uighur -- ran reports on riots in the region which killed around 200 people.

The vast western area has for years seen sporadic unrest by Uighurs, which rights groups say is driven by cultural oppression, intrusive security measures and immigration by Han Chinese.

Beijing attributes the unrest to religious extremists and separatism.

In late October, police said three Uighurs drove a vehicle into crowds of tourists opposite Beijing's Tiananmen Square, killing two people and injuring 40, before crashing outside the Forbidden City and setting their vehicle ablaze. All three attackers died.

Tohti had warned against the temptation to stigmatise Uighurs after these events.

On Saturday authorities said six people died in explosions and another six were shot dead in Xinjiang.