BEIJING - A Chinese man attacked two American tourists and a Chinese tour guide in downtown Beijing on Saturday shortly after noon, leading to the death of an American man and injuries to the other two, both women.

The attacker then killed himself by jumping from the second storey of the historic Drum Tower, a popular tourist site, after the incident, a spokesman with the Beijing Municipal Government Information Office said.

US President George W. Bush, who is in Beijing for the Olympic Games, said he and his wife Laura are saddened by a deadly attack on an American family and their Chinese tour guide in Beijing, saying their thoughts and prayers are with the victims and their families.

He added that the US government has offered to provide any assistance the family needs.

Chinese Foreign Ministry paid high attention to the attack against US citizens. Vice Foreign Minister He Yafei promptly went to the hospital to see the injured US citizen and her Chinese tour guide and informed the US ambassador to China Clark Randt.

The spokesman did not specify the method of attack, which took place at about 12:20 pm on the second story. The motive for the attack remains unknown.

He said the American nationals had entered China on tourist visas but did not disclose their identities.

The two injured women are in stable condition at a hospital.

The attacker was identified as 47-year-old Tang Yongming from the eastern city of Hangzhou, Zhejiang Province, according to an ID card found on his body.

An initial investigation showed that Tang had no "fixed residence or job" in Hangzhou when he came to Beijing on August 1, a spokesman with the Beijing Municipal Public Security Bureau said.

Zhejiang police said Tang had worked for a meter factory in Hangzhou but had resigned. They didn't say why or when.

He and his wife divorced in 2006. He sold his apartment the same year and had lived in a rented house ever since.

"Tang has no criminal record. His neighbors said they hadn't seen any abnormal behavior from him before left Hangzhou," a spokesman with the Zhejiang Provincial Public Security Bureau said.

The spokesman said Tang was not a petitioner; that is, he had not so far submitted any kind of complaint to government officials.

Tang vacated his rented house on August 1, saying he would move elsewhere to do business, the spokesman said. Tang didn't specify where he would go or what business he intended to do.

Tang has a 21-year-old son who was once sentenced to six months in prison for theft, he said.

"We are now looking for Tang's ex-wife and elder brother, hoping to find out what he did before the incident in Beijing and figure out his motivation," he said.

On Saturday, the United States Olympic Committee (USOC) issued a statement on its official website, identifying the American nationals as relatives of a US Olympic volleyball coach.

"The United States Olympic Committee has learned of an incident that occurred earlier today involving two family members of a coach for the United States Olympic Men's Indoor Volleyball Team," the statement said.

"While at the Drum Tower in central Beijing, the two family members were stabbed during an attack by what local law enforcement authorities have indicated was a lone assailant. One of the family members was killed and the other seriously injured.

"... the USOC is working closely with the United States Embassy, United States law enforcement authorities and local law enforcement authorities," it said.

Located in central Beijing's Dongcheng District, the Drum Tower is a two-storey wooden building almost 47 meters high.

The Drum Tower (Gu Lou in Chinese), together with the nearby Bell Tower (Zhong Lou), was used by the ancient Chinese to tell time. Built in 1272 and rebuilt after two fires, the two towers tolled the hours during the Yuan, Ming and Qing dynasties (1271-1911).