Mainland police say they have broken up a terrorist group linked to a clash with the authorities in Xinjiang last week in which 21 people died.
Public security authorities said the assailants were linked to a jihadist group and said the mastermind of last Tuesday's attack had been interrogated five years ago. They did not say if the jihadist group had overseas links.
At a memorial service yesterday, the 15 police officers and government workers killed in the attack were hailed as martyrs. Six of their assailants also died at the scene of the attack in Bashu county, Kashgar, making it the deadliest incident in the autonomous region since July 2009, when nearly 200 people died in rioting in the regional capital, Urumqi.
Eight of those who died were police officers. The other seven included a township Communist Party secretary, a publicity official and workers. Ten of the police and government workers who died were Uygurs.
A notice on the regional government's internet news portal said eight assailants had been captured on the spot, with 11 others who fled to other cities arrested over the past few days. Police had confiscated 20 explosive devices, "jihadist" flags, substances that could be used for making bombs and a number of knives.
It said the police had investigated a member of the group in July 2007 for suspected involvement in terrorism but that he had been released as there was insufficient evidence to press charges.
Three government workers checked a home last Tuesday after receiving a tip-off. A person in the house alerted their associates nearby, leading to the capture of three government workers, who were later killed.
More police officers and government personnel rushed to the scene and fighting intensified. The assailants set fire to a room the police and workers had been forced into, killing nine people.
Three assailants on motorcycles rushed to set fire to the archives office and hostel at the local police station.
When asked why only the head of the local police station had been armed during the raid, regional government spokeswoman Hou Hanmin said local officials were caught off guard because they did not think they were dealing with terrorists.
"No one had even thought that such a big thing would happen," she said. "And no one had even thought that the people living there were terrorists."
Some government workers had built up a good relationship with the assailants through helping them apply for government certificates, she said.
The group's members watched violent jihadi videos, organised "underground Koran classes" and had spread extreme religious teachings since September, the government notice said. It said they had started training for attacks in December and were planning a "major attack" in Kashgar this summer.
Deputy Public Security Minister Meng Hongwei, director of China's anti-terror office, blamed the attack on separatism, religious extremism and terrorism.
But Dilshat Rexit, a spokesman for the World Uygur Congress, said he suspected the terrorism claims were just an excuse to oppress Uygurs.