Eleven people were killed in suicide bomb attacks on government offices and a subsequent police shoot-out in the restive province of Xinjiang as Muslim militants stepped up their campaign of violence in China's "wild west" to highlight their demand for separatism.
It was the second major attack in the province in less than a week. China has identified militants seeking an independent "East Turkestan" homeland for Muslim Uighurs as the biggest threat to security at the Olympics.
Two suicide bombers armed with home-made grenades and a security guard died in the dawn attacks on government offices in the town of Kuqa, in the south of Xinjiang, more than 1,800 miles from the Chinese capital, Beijing. Police subsequently shot dead eight assailants, the Xinhua news agency reported. The bombers travelled by taxi to their targets.
Security was high on the agenda at the weekend, with the bombings yesterday and the killing on Saturday of the father-in-law of the US men's volleyball coach in a knife attack at a popular tourist spot, the Drum Tower, in the capital. Another family member was injured.
Yesterday's bombings followed an attack last week in which separatists drove a truck into a group of policeman who were out jogging in Kashgar, in the far west of the province, before throwing home-made grenades and attacking the officers with knives, killing 16.
Wang Wei, secretary general of the Beijing Games organisers, said Xinjiang separatists were engaged in a campaign to use the "platform of the Olympics to amplify the effects" of their actions. Keen to reassert control, police have sealed off the entire county and closed shops and businesses.
The province is home to eight million Uighurs, a Turkic ethnic group who share linguistic and cultural bonds with central Asia, and is an area from where China gets much of its oil and gas. Uighurs used to dominate the region, but Han Chinese now make up the majority of the province's 20 million people after an intensive resettlement policy in recent years.
The Islamist separatists want autonomy and have been linked to a number of recent attacks. Last week they issued a chilling video containing footage of a bomb factory and urging people to "stay away from the Games". The separatists have also been linked to a bus bombing in the city of Kunming last month, five days before which a Uighur militant was discovered carrying 100 detonators.
With 2.3 million soldiers, 800,000 reservists and a People's Armed Police of 1.5 million, the People's Liberation Army is the biggest army in the world, but it has had a tough job keeping a lid on violence in Xinjiang. Thousands of soldiers are stationed there to protect the valuable oil and gas deposits. Long lines of army trucks can be seen driving alongside the network of new highways criss-crossing the desert province.
The authorities in Beijing say the Uighurs in Xinjiang are violent Islamist fundamentalists trying to cut off the province from Chinese rule. Human rights groups regularly complain about how the Uighurs are treated and accuse Beijing of using its support for Washington's "war on terror" against al-Qa'ida as an excuse for clamping down on their activities.