But rights groups for the mostly Muslim Uygurs blame unrest on economic inequality and religious repression, and Washington has raised concerns about discrimination.

, a mouthpiece for the ruling Communist Party, slammed the US government and media for what it said was its role in the violence.

“For fear of a lack of chaos in China,” it said in a commentary, the US was “conspiring to direct the calamity of terrorist activities toward China”.

“America’s double standards on the issue of countering terrorism is no different than incitement and indulgence ... How is this different than those who act as accomplices to terrorism?” it said.

It asked if the 9/11 attacks and Boston marathon bombings in April meant “America’s ethnic and religious policies also have problems”, while rejecting such linkages in China.

“The violent terrorist incidents in Xinjiang are not an ethnic issue or a religious issue,” it said, calling the “massacres” of officials and bystanders “inhumane”.

According to the official Xinhua news agency, “knife-wielding mobs” attacked police stations and other sites in the town of Lukqun last Wednesday before security personnel arrived and opened fire. At least 35 people were killed.

Two days later, Xinhua said, more than 100 “terrorists” provoked “riots” in the prefecture of Hotan, attacking people “after gathering at local religious venues”.

Last Friday a US State Department spokesman said it was “deeply concerned about ongoing reports of discrimination against and restrictions” on Uygurs in China.

He said the US urged a “transparent investigation” but did not want to “draw broader conclusions” about the incidents.

The Global Times accused members of the "East Turkestan" movement of being trained by Syrian opposition forces fighting the government of Bashar al-Assad before returning to Xinjiang to plot attacks.

This appears to mark the first time Beijing has blamed a group in Syria and fits a common narrative of the government portraying Xinjiang's violence as coming from abroad.

The Global Times, a tabloid owned by the People's Daily, said that some members of the "East Turkestan" faction had crossed from Turkey into Syria.

They "participated in extremist, religious and terrorist organisations within the Syrian opposition forces and fought against the Syrian army", it said. "At the same time, these elements from 'East Turkestan' have identified candidates to sneak in to Chinese territory to plan and execute terrorist attacks." Authorities had arrested a 23-year-old "terrorist", known in Chinese as Maimaiti Aili, belonging to the East Turkestan Islamic Movement (ETIM), the report said, adding that he had taken part in the Syrian war.

The Global Times quoted a statement from Maimaiti Aili as saying that the ETIM "specifically asked me to carry out sabotage activities in Xinjiang and enhance the 'struggle level'".

The Uygur World Congress hit back at what it called China’s “distorting accusations”.

“Uygurs live in an outdoor prison,” it said in an emailed statement, adding that their “resistance” had “nothing to do with terrorism”.

On Saturday, large sections of the Xinjiang capital Urumqi were shut down as military vehicles took to the streets with at least 1,000 personnel from the People’s Armed Police, part of China’s armed forces responsible for law enforcement and internal security during peacetime.

Beijing’s assertive presence on the ground comes ahead of the sensitive anniversary of riots between Uygurs and China’s ethnic majority Han four years ago.

The Muslim fasting month of Ramadan is also expected to begin next week.

In recent decades many Han Chinese have relocated to Xinjiang, which is rich in coal and gas, provoking friction.

The two communities tend to live in separate neighbourhoods in Urumqi, and a greater security presence could be seen in the Uygur area on Monday.

Paramilitary forces stood in clusters every 100 metres or so around the grand bazaar, and police vehicles drove by occasionally.

Beijing denies repressing China’s ethnic minorities, who make up less than 10 per cent of the national population and enjoy some preferential policies.