KASHGAR, China(AP) A stolen truck used to run down jogging policemen in western China was parked overnight near the police station, with the assailants waiting to strike during the officers' morning routine, according to state-run media.
New details about Monday's attack - one of the most audacious in this restive Muslim territory - came with China on high alert for other violence or unrest that might embarrass the country ahead of Friday's start to the Olympic Games in Beijing.
The attackers, who killed 16 border police in the city of Kashgar, confessed they had spent one month watching the police, the Xinhua News Agency quoted police as saying.
On the day of the attack, one of the assailants staked out the police station and used a mobile phone to inform his truck-driving partner when the 70 policemen had begun their morning jog along a major road, Xinhua reported late Tuesday.
The driver got into the truck that had been parked all night near the station and drove into the runners from behind at top speed, Xinhua said. The other attacker threw a homemade bomb at the police station's gate before using a knife to stab officers hit by the truck, the report said.
The attackers were Abdurahman Azat, a 33-year-old vegetable peddler, and Kurbanjan Hemit, a 28-year-old taxi driver, both of Kashgar, Xinhua quoted the city's Communist Party secretary, Shi Dagang, as saying.
Before the attack, the assailants wrote a letter saying they had to wage ``holy war,'' and that their mission was more important than their lives and mothers, Xinhua quoted Shi as saying.
It was not immediately known if the attackers belonged to radical Islamic groups that the government has blamed for a series of sporadic shootings, riots and bombings in the past several years. Police said they found nine homemade explosives similar to those recovered last year in raids on a training base of the East Turkistan Islamic Movement, Xinhua reported.
The group is reportedly based along China's borders with Afghanistan and Pakistan and linked to al-Qaida and is listed by the State Department as a foreign terrorist organization.
Before Monday's attack, Kashgar and other parts of Xinjiang were on high alert. The special security measures were in full force Wednesday.
Security was especially tight around major transport points. Vehicles passing through a tollbooth on a highway north of the city were being told by police to pull over so that trunks and identification cards could be checked. Only one officer displayed a firearm, a short-barrel shotgun worn over his shoulder.
Some ID cards were taken to a battered wooden desk on the side of the road, where a laptop was set up, allowing the officers to check the documents against a police database.
``We're familiar with many of the local drivers. Those we haven't seen before get checked with the computer,'' said one officer, adding that the checkpoint was established in April for the Olympics.
At Kashgar's railway station, police demanded that an Associated Press photographer stop taking pictures because the area had been declared a military zone. A sign at the station said train service was suspended Wednesday because of wind storms.
Police also asked AP journalists to leave a bus depot where buses from Pakistan arrive. Officers said only arriving passengers were allowed at the station.