China on Monday blamed Muslim separatist "terrorists" trained in neighbouring Pakistan for an outbreak of deadly violence and imposed heavy security in a bid to prevent further unrest.
Nineteen people, five of them suspects, were killed in two separate incidents in the ancient Silk Road city of Kashgar at the weekend in the latest wave of violence to hit the Xinjiang region, home to a mainly Muslim Uighur minority.
Two more suspects, both of them Uighurs, were "executed on the spot by police who were in the process of capturing them" on Monday, the Kashgar local government said in a statement.
This file photo taken on July 10, 2009 shows trucks full of Chinese soldiers patrolling the streets of Kashgar, in China's farwest Xinjiang region after some of the worst deadly ethnic violence in decades hit the province
In an earlier statement on its website it said the assailants behind an attack on a restaurant that left six dead on Sunday had learned explosive-making skills in terrorist-run camps in Pakistan.
"The heads of the group had learned skills of making explosives and firearms in overseas camps of the terrorist group East Turkestan Islamic Movement (ETIM) in Pakistan before entering Xinjiang," the online statement said.
The attackers adhered to "extremist religious ideology" and advocated "jihad", the statement also said.
Chinese authorities have accused the ETIM, which wants an independent homeland for Xinjiang's Uighurs, of orchestrating attacks in the region on many occasions.
The United States and the United Nations have listed the group as a "terrorist" organisation, and China has previously said it has operations in Pakistan as well as Afghanistan.
Pakistan said it would "continue to extend its full cooperation and support" to China's government against the ETIM.
However, Xinjiang expert Michael Dillon told AFP there was little evidence the group had any links to Pakistan.
"What we're seeing now is a repeat of China's complete unwillingness to see that unrest inside its borders might stem from poor conditions," said Dillon, an academic and author of the book "Xinjiang, China's Muslim Far Northwest".
Many of Xinjiang's roughly nine million Turkic-speaking Uighurs are unhappy with what they say has been decades of political and religious repression, and the unwanted immigration of China's dominant Han ethnic group.
The tension has triggered sporadic bouts of unrest in the resource-rich and strategically vital region bordering eight countries, including Afghanistan and Pakistan.
In Washington, a Uighur exile leader who opposes the use of violence said China was to blame for creating instability in the area after major disturbances broke out in 2009.
"The Chinese government must take responsibility for creating this climate of fear, and must take steps to end its brutality against Uighurs in order to create peace in the region," said Alim Seytoff, president of the Uighur American Association.
Sunday's attack came less than 24 hours after eight people were killed and more than 20 others hurt at a night market in Kashgar by two knife-wielding assailants, according to authorities.
Police also reportedly shot dead five attackers at the weekend. The two suspects killed on Monday died in the suburbs of the city, the Kashgar government said, without giving further details.
Some state media reports on Monday blamed both weekend incidents on "terrorists".
There was a heavy police presence on the streets of Kashgar and few Han Chinese in evidence.
Dozens of police carrying machine guns blocked the street where Sunday's attack took place, while soldiers and police stood guard at the city's main People's Square.
A 51-year-old Han woman from Xinjiang's capital Urumqi who identified herself only by her surname, Lu, said she was in Kashgar on business, and was concerned about her safety in the city.
"My family is worried about me visiting Kashgar. I won't take a taxi this time as most of the drivers are Uighurs. I've asked a friend to pick me up instead," she told AFP.
A Uighur man in Kashgar who asked not to be named said he feared the city's Han population could launch revenge attacks. "I'm worried for my life," he said.
The weekend unrest came after more than 20 people were killed last month in a clash with police in the remote city of Hotan, when state media quoted a Xinjiang official calling the clash a "terrorist" attack.
But Uighur activists called it an outburst of anger by ordinary Uighurs and said security forces killed 20 people during the unrest.
In the nation's worst ethnic violence in decades, Uighurs savagely attacked Han Chinese in Urumqi in July 2009 -- an incident that led to retaliatory attacks by Han on Uighurs several days later.
The government says around 200 people were killed and 1,700 injured in the violence, which further weakened the authoritarian Communist Party's claims of harmony among the country's dozens of ethnic groups