More than 40 people, including students and trainers, were injured on Sunday in a clash during a military education class in a high school in Longshan county, Hunan Province.

Forty students, one military trainer and one teacher were injured in a physical clash during a military education and training course given to high school freshmen in Huangcang High School of Longshan county, local government said in a statement late Monday.

The conflict started when a freshmen class resisted a military trainer who was being too harsh on students and even stepped on their backs to force them to do push-ups, according to Shanghai-based news website thepaper.cn.

The class advisor then intervened but was beaten by the military trainer and some more trainers joined the fight, the website reported. 

The military trainers were from reserve forces sent by the local people's armed forces department run by the People's Liberation Army, news portal people.com.cn reported on Monday.

Order has been restored in the school and all the injured have received medical treatment.

Twenty-five remained in local hospital by 5 pm on Monday, said the statement.

Local police are investigating the case, the government said.

Pictures of injured students wearing uniform have been widely spread online and aroused controversy, with many complaining about their own experiences of harsh military training courses.

In China, most college and high school freshmen have to endure several weeks of military training.