HANOI, Sept. 1 (Xinhua) -- Four children from Vietnam's central Quang Ngai province drowned when having a bath in a local river, the provincial police said on Saturday.

Two sisters aged 10 and 15, and two twin brothers aged nine from two families in Nghia Hanh district had a bath in Ve River on Friday afternoon and slid into a deep hole in the river. By Saturday morning, all the four bodies had been found by local police and residents.

"Drowning is a silent epidemic claiming more than 2,000 children's lives per year in Vietnam," an official from the World Health Organization in Vietnam told Xinhua recently, adding that the rate of child drowning in Vietnam is higher than other Southeast Asian nations and 10 times higher than that of developed countries.

The official said that many deaths caused by drowning in Vietnam were preventable, and the drowning rate among local children would fall if adults supervise kids' activities more closely, and more kids were provided with survival swimming and water safety skills.