Beijing - Chinese officials said Thursday they have smashed an international terrorist group that planned to attack an Olympic Games football site in the eastern city of Shanghai.

"We have obtained information that international terrorist organizations would likely launch an attack against an Olympic venue in the city during the Games," the official news agency Xinhua quoted Cheng Jiulong, Shanghai Public Security Bureau deputy director, as saying.

"We have staged raids and cracked a group of terrorists," said Cheng, who is also head of the Shanghai security office for the Olympics.

Xinhua gave no details of the background or size of the terrorist cell, or whether it was linked to a group named previously as a potential threat to the Games beginning August 8.

The group had threatened to kidnap athletes and journalists attending the Olympics in Beijing and Shanghai, officials said.

Shanghai will host 12 Olympic football matches. The city's main football stadium has been closed for security checks since Sunday.

Police have stepped up security at sporting venues, roads leading to them and athletes' accommodation. Security has also been increased in other cities where Olympic events are taking place.

There have been no reports of major terrorist incidents in China in recent years.

Two bombs exploded on public buses in the south-west city of Kunming on Monday, injuring two people. Officials said there was nothing to link the blasts to terrorists. (dpa)