A total of 13 vocational school students were injured early Wednesday morning by a gang of youths armed with knives in south China's Hainan Province, said local authorities.

Two seriously wounded students were being treated at the Haikou City People's Hospital. But their injuries were not life threatening, said a spokesman with the hospital.

Around midnight Tuesday, four students of Hainan Technology and Vocational Institute were attacked outside the school by youths from the nearby villages after a dispute, some witnesses said.

Police arrived at the scene about ten minutes after they were alerted, and left after questioning students, they said.

Then at around 2 a.m. Wednesday morning, more village youths with knives joined the previous attackers and barged into two dormitories of the school and slashed nine students.

Some of the school's students previously had had altercations with the village youths, witnesses said.