Fifteen children have died in a school bus crash in China - just one day after the government issued strict guidelines to prevent such accidents. The children were killed when their bus drove into a ditch as it tried to avoid a motorised rickshaw in Jiangsu province. Officials said some children drowned and others suffocated to death. This accident comes weeks after an overloaded minibus crashed, killing 19 kindergarten children. This latest accident happened late on Monday on a country road in Fengxian county. The bus, operated by a local primary school, was taking children home. The ditch it drove into was filled with about 60cm of water, according to a micro-blog posting by the local public security bureau. \"Water got into the bus and because the pupils were pressing down on each other. Some of them drowned. Others suffocated,\" said the posting. It added that the driver is now in detention. Officials were keen to stress that the bus was not overloaded at the time of the accident. It could carry 52, but apparently had just 29 on board when the crash happened. These officials perhaps want to draw a distinction between this crash and the one last month in Gansu province. On that occasion, more than 60 youngsters had been crammed into a minibus that originally had just nine seats. It led to an outcry of public anger. But questions are already being asked about this latest accident, particularly in internet chat-rooms and on micro-blog sites. \"School buses simply cannot be trusted at all,\" read one posting. The day before this crash, the central government issued draft guidelines to guarantee children\'s safety. They call for compulsory checks on buses and their drivers.