Deliberate explosions on three Chinese buses killed at least three people and injured 14 in the southwestern city of Kunming on Monday, media said, amid a security clampdown ahead of next month's Beijing Olympics.
The official Xinhua news agency blamed the blasts on "sabotage" and said police had started roadside checks in Kunming, the capital of Yunnan province, to try to find the person or persons responsible. It did not elaborate.
The attack happened less than three weeks before the Beijing Games which China has warned could be a target of terror attacks.
An explosion on one bus happened at the Panjiawan stop at 7.10 a.m. and the second blast was nearby, Xinhua said. Pictures showed a gaping hold in the side of one of the buses and glass scattered in the street.
Another explosion occurred near Minshan, also nearby, the semi-official China News Service said in a report on its website (www.chinanews.com.cn).
Two people were killed at the scene and one died on the way to hospital, the report said.
But a Yunnan government official said by telephone from Kunming there had only been two explosions, and declined further comment.
China has occasionally witnessed bus explosions staged by disgruntled farmers or laid-off workers wanting to air grievances over poverty, demolitions or corruption.
The Kunming blasts also came two days after Yunnan police opened fire and killed two rubber farmers in the province's Menglian county in a clash that also saw 41 police officers injured.
The clash was sparked when police tried to arrest five people in Menglian for allegedly attacking a local rubber company in a long-running dispute between farmers and the private firm, state media said.
Chinese authorities have directed officials to redress local residents' grievances and act on complaints to try to resolve disputes and ensure a "harmonious social atmosphere" in the Olympics period.
But the country has struggled to curb unrest. In June, 30,000 residents rioted in the streets of Weng'an, in Guizhou province, after allegations spread that police had covered up the rape and murder of a local teenage girl.
