HOHHOT - Seven officials have received punishments ranging from being dismissed from posts to intra-Party warnings following the drowning of seven teenagers in a reservoir in North China's Inner Mongolia Autonomous Region, local authorities said Thursday.

The seven high school boys drowned while going for a swim in Budong River Reservoir in Shangdu county Sunday afternoon, said the county government.

According to the government, the tragedy was partly due to slack supervision of the reservoir, which is under the management of the county water conservancy bureau.

Another factor leading to the deaths was that the Shangdu County High School, where the seven boys studied, advanced the starting date of the autumn term to August 7 and didn't look after the students well while holding a social practice activity, said the government statement.

The autumn semester of Chinese high schools usually starts around late August.

Among the punished, Ge Youwang, head of the county water conservancy bureau, was suspended from his position, and two leaders of the reservoir management department were removed from their posts.

Jia Yiding, principal of the high school, received an intra-Party warning.

According to previous reports, staff from the reservoir said they heard the students crying for help at around 4:46 pm Sunday and immediately called for help.

The seven students were pulled out of water after more than 140 armed police and firefighters searched for two hours. They were rushed to the hospital, but died after emergency medical treatment failed.