Chua Chin Hon wonders if there'll be VIP cancellations at the Olympics.

In Beijing

KASHGAR, China's western-most city, is over 4,000km, or a six-hour flight, away from Beijing.

But the huge distances involved would not have softened any of the psychological blow that came from today's audacious terror attack there, just four days before the Olympics opening ceremony.

The heavy death toll and the modus operandi of the attackers were all the more shocking given that a heavy security blanket had been thrown around Beijing and restive provinces such as Xinjiang, where Kashgar is located.

According to the official Xinhua news agency, two suspects rammed a dump truck into a team of policemen who were out for their Monday morning jog. The attackers then hurled explosives and used knives to hack at some of the policemen after their truck veered off the road and crashed into an electricity pole.

The attack killed at least 16 policemen and injured another 16, making it one of the most deadly in recent years. The two attackers were subsequently arrested in a raid, though they were not immediately identified by state media reports.

Chinese officials routinely cite separatist groups, such as the "East Turkistan Islamic Movement" in Xinjiang, as the top security threat for the Beijing Olympics.

The attack in Kashgar, which appears to have been planned with cold precision for months, then raises many uncomfortable questions about the intelligence gathering capabilities of the Chinese security forces, as well as their ability to preempt other attacks elsewhere.

With over 80 top foreign leaders and a legion of global business elites flying into town on Friday for the Olympics opening ceremony, these questions can't come at a worse time for China.

The biggest question, however, is whether any major world leader will be prompted to cancel his or her trip to the Olympics as a result of today's attack.