Police in north-western China's Xinjiang region on Tuesday stepped up security following a deadly attack against paramilitary police which authorities suspected to be a terrorist plot by ethnic minority Uighurs, reported dpa.
A Washington DC-based association of exiled Uighur Muslims from China on Tuesday called for independent accounts of the attack, saying details remain unclear.
The attack Monday against a group of armed police while they were jogging outside their barracks in Kashgar city left 16 officers dead and 16 others injured, according to the official Xinhua news agency.
Xinhua said the two attackers, both Uighurs, have been arrested.
Authorities in Xinjiang boosted police manpower at road checks, intensifying inspections of bags and vehicles and stepping up surveillance of public places including government office buildings, schools and hospitals, said Xinhua.
In the provincial capital Urumqi, police used wireless identification verification devices in routine street patrols to run documents through a police database to find blacklisted suspects at large, the agency reported.
The Chinese government did not issue any other details about the incident, and no footage was shown on state-run television. One photograph in the China Daily showed rescuers carrying an injured police officer on a stretcher.
The US-based Uighur group said it condemned all acts of violence and expressed fears that the incident reported by Xinhua will be used by China to increase suppression of Uighurs and exacerbate tensions with Han Chinese.
"The Uighur people do not support acts that engender bloodshed," exile activist Rebiya Kadeer said in the group's statement.
"I urge the Chinese government to refrain from using this incident to crack down further upon peaceful Uighurs."
The group said that in the run-up to the August 8-24 Olympic Games in Beijing, Uighurs have experienced higher rates of execution and detention, in addition to forced relocation, police monitoring, passport confiscation and the destruction of places of worship.
The group urged the international community to view Chinese government accounts regarding Uighur terrorist acts with caution, as it said authorities consistently fail to provide evidence to back up their claims.
Two Japanese reporters were detained for two hours and beaten in a hotel by paramilitary police late Monday while trying to report on the incident in Xinjiang. They suffered minor injuries.
Two AFP reporters were briefly detained in Xinjiang recently, despite China's earlier promises to provide free access to reporters for the Olympics.
According to Xinhua's account, one of the two attackers drove a truck into more than 70 police who were jogging near the Yiquan Hotel in a regular morning exercise at about 8 am Monday. The other suspect threw an explosive device toward the gate of the police station, the agency said.
The driver then abandoned the truck and threw explosives at the officers, Xinhua cited police saying.
Police found 10 homemade explosives, a homemade handgun and four knives in the vehicle, Xinhua said.
It said the 16 injured police were still being treated at the Kashi Prefectural People's Hospital, four of them in intensive care unit.
One local resident who worked nearby said there was an explosion but said she was warned in a company meeting not to talk about it with outsiders.
In the run-up to the Olympics, China has accused the East Turkistan Islamic Movement of plotting terrorist attacks to try to sabotage the Olympics.
Turkic speaking Uighur Muslims rioted and attacked the majority Han Chinese during the 1990s due to resentment against what many Uighurs and rights groups consider to be repressive Chinese rule. China has also encouraged Hans to move to Xinjiang, diluting the population and taking jobs.