Twenty people have gone missing in central Vietnam after a bus carrying 37 passengers was washed away in flood waters in Ha Tinh province.Local police said the accident took place this morning and they have rescued 17 persons. The missing people include at least four women and five children. According to Vietnam 's Central Steering Committee for Flood and Storm Prevention control, continuous rain in the past four days has caused massive flood in central Vietnam, killing 20 people so far. The flood has submerged houses and crops, disrupted transportation and heavily impacted local people's lives.