Dang Huu Dung, a professor at the Agriculture and Forestry University, received acid burns to a third of his body, the Thanh Nien newspaper website reported, quoting the head of the burns unit at Cho Ray Hospital in southern HCM City.

The professor told reporters that a former student used a large bowl to splash him with the acid before chasing him with a knife, the report said.

Thirteen nearby students were also burned, it said.

Police on Monday arrested Tran Xuan Thanh, 28, who finished his four-year course in 2006 but did not graduate because he failed the English test on mechanics, Thanh Nien reported.

It said the former student allegedly told police that he recently asked Dung to help him apply for another English test but the professor refused, saying it was too late.

"I thought Dung was not fulfilling his responsibilities towards his students," Thanh allegedly told police, adding that he took five litres (1.3 gallons) of acid to the school.

Learning is greatly valued in Vietnamese society and places at university are highly coveted.

Agence France Presse - August 25, 2009