(Updates death toll, adds separate bus accident) BEIJING, July 16 (Reuters) - A bus carrying school children slipped from a ferry into a river in eastern China on Monday, killing at least eight people and leaving around a dozen missing, officials said. "According to witnesses, 20 to 30 passengers were on board, including children going to summer school, and we don't know the exact figures yet," Wang Xiaoyan, publicity director of the Yugan county government in Jiangxi province, was quoted by Xinhua news agency as saying. Rescuers had been able to hoist the bus from the bottom of the Xinjiang River, recovering seven bodies from it, including those of two children and two women, Xinhua said in report late on Monday. Earlier in the day, rescuers had managed to find six people, one of whom died. The accident took place around 11:00 am local time, Xinhua said, adding that an investigation into its cause was under way. On Sunday, a minibus overturned in a remote part of southwest China, killing 12 people and injuring eight, Xinhua said in a separate report on Monday, one of a string of fatal bus crashes in the country in the past few days. The bus ran through roadside barriers and fell more than 10 metres on Sunday in the mountainous and underdeveloped province of Guizhou, Xinhua said. Also on Sunday, a bus collided with two cars that had just been in an accident on an expressway in the southern region of Guangxi, killing 3 and injuring 46, Xinhua said.