Thousands of persons are being evacuated from around a lake and a river at risk of bursting in south-west China's earthquake-affected zone, said relief officials on Saturday. The disaster relief headquarters in the Beichuan County said it received reports of water levels reaching danger point at the Laoyingyan section of the Qianjiang River on Saturday. The river has been blocked by landslips caused by the earthquake. "It hasn't burst yet, but we asked people to leave because we need to prepare for the worst,' said an official. He said experts were conducting surveys of the river and considering whether to blast the blockages to discharge the water. Hundreds of rescuers and residents were seen leaving Beichuan on Saturday. The headquarters said 7,227 persons died in Beichuan, 5,894 are missing and 4,459 are buried. At the Hongguang Township in Qingchuan County, authorities are evacuating about 2,000 persons downstream of the Qingzhu River as there warnings of flooding. Multiple landslips blocked parts of the river and formed a large stretch of water, which experts with said exceeded 10 million cubic meters. More debris falling in after aftershocks were likely to continue to push the water level up, said experts. "If the water level rises, it will endanger more than 2,000 persons staying downstream,' said one expert. Death toll is 28,881 The death toll has risen to 28,881 as of Saturday, while 198,347 people were injured, according to the Information Office of the State Council. Officials said 145 aftershocks had been monitored since May 12.