More than 4,000 students were affected when classes were suspended in their schools following a gas leak in Gaoqiao Town of Kaixian County, southwest China's Chongqing Municipality, said an official with the local government.

Three schools near the site of the leak were closed and another three used to house evacuees, said Jiang Bocheng, head of the Kaixian Education Committee.

None of the students from the six primary and high schools in the town were affected by the leak, added Jiang.

"The school authorities took timely emergency measures to evacuate students and suspend classes after the incident," he said.

"We will try our best to resume classes for third graders in junior high school by Wednesday as they will take senior high school entrance exams soon," he said.

"Time to resume lessons for other students will be determined by when the incident is completely over," he added.

More than 10,000 residents living within a kilometer of the leak were evacuated and measures to cap it are still ongoing.

Local government workers are monitoring the air and water quality within one kilometer of the leak and reporting the results every hour. No water or air pollution has been reported.

The leak was discovered at the well belonging to the China National Petroleum Corporation's Sichuan Provincial Petroleum Administration Saturday morning. There have been no reports of casualties.

The gas well is within the vicinity of the Luojia No.16H Gas Well where a deadly gas blowout killed 243 people on Dec. 23, 2003.

Ma Fucai, then CNPC's general manager, resigned in April 2004 for his negligence in security measures that led to the deadly accident.

(Xinhua News Agency March 28, 2006)