Kashgar, China ? Blood was washed off the road. Debris was cleared away. And authorities said peace had been restored Tuesday in China’s restive Muslim region where 16 police were killed in an attack that may have been timed to overshadow Olympic celebrations.

But there were plenty of other signs suggesting all was not well in Kashgar, this ancient Silk Road city near the border with Afghanistan and Pakistan at the opposite end of China from Beijing.

Townspeople were reluctant to talk about Monday’s brazen assault. Police stepped up security checks and put schools, hospitals and government offices on heightened alert, state-operated media and locals said. Slogans on billboards, walls and buildings urged people to create a more secure and harmonious society.

The precautions underscored the Chinese government’s sensitivity to anything that could sour its plans for the Beijing Games to be a pivotal moment of national glory and global acceptance, despite continuing criticism of its record on human rights.

Kashgar is 2,200 miles west of Beijing, in the far western region of Xinjiang – a vast, rugged territory home to a Muslim minority called the Uighurs (WEE’-gurs). They have a long history of pushing for independence, and Chinese authorities have blamed a series of sporadic bombings, shootings and riots in recent years on Uighur extremist groups.

One such group, believed to be based in the remote tribal regions of Pakistan, released a video tape last month threatening to target the Olympics.

But many Uighur activists accuse Chinese officials of exaggerating the terrorism threat to justify a crackdown on the ethnic minority. They claim the clampdown has greatly intensified during the run-up to the Olympics, which start Friday.

Monday’s attack was one of the most audacious in years.

Two men – a taxi driver and a vegetable seller – drove a truck into a group of 70 border police during their routine morning jog in a northwestern neighborhood, where several popular tourist hotels are located, the state-run Xinhua News Agency reported.

The attackers, ages 28 and 33, tossed homemade bombs at the officers and stabbed them with knives, killing 16 and wounding another 16 before being captured, the report said.

One of the attackers lost a hand when the homemade explosives blew up, about 100 yards from the border police base. Police later recovered additional explosives, a homemade gun and “propaganda materials about a holy war,” state media said.

By Tuesday, authorities had meticulously cleaned up the attack scene on a six-lane, tree-lined street in front of the low-budget Yiquan Hotel, a low-rise building covered in dusty white, yellow and maroon tiles.