BEIJING: China stepped up security around Olympic sites on Tuesday following recent violent incidents but a Games official repeated assurances that visitors were in no danger.

The tighter security included extra new checks on journalists entering the Olympic media village and an armoured personnel carrier parked in front of the main Olympic press centre.

The moves come a week after the fatal stabbing of a US Olympic coach's relative on Saturday by a Chinese man and violent incidents in western China that Beijing has blamed on Muslim militants targeting the Games.

"From my perspective, I think it is meant to be protective, to safeguard security and safety and all the athletes and everybody," Wang Wei, vice president of the Beijing Games organising committee, told reporters.

"With regards to the stabbing incident, I think relevant authorities may have increased the security level."

In Saturday's attack, an unemployed Chinese man killed American Todd Bachman and also stabbed his wife and their local tour guide at a popular tourist spot in Beijing, raising security concerns throughout the Olympic community.

The attacker killed himself afterward.

Militants have also staged two attacks in the Muslim Xinjiang region this month that have left 28 people dead, according to official Chinese sources. China has repeatedly warned of an Islamic terror threat to the Games from Xinjiang, but Wang sought to cool security fears on Tuesday.

"I do not think there is a real threat. You are safe," Wang said.

Bachman was the father-in-law of US men's volleyball coach Hugh McCutcheon. His wife, Barbara, was in a serious but stable condition at a Beijing hospital, the US Olympic Committee said Monday.

China has introduced unprecedented security to safeguard the estimated 450,000 foreign visitors in Beijing for the Games, deploying more than 150,000 police and other personnel to patrol the city.

Authorities had said after the stabbing that security at tourist spots across Beijing would be stepped up further with increased checks for sharp implements.

Beijing is normally a very safe city for foreigners. -AFP/yt