Image copyright Getty Images Image caption The children were aged between 10 and 16 but under Chinese law, blood donors must be over 18

Police in China have arrested seven people thought to be behind a scheme that forced schoolchildren to give blood, state media says.

According to police, at least eight children aged between 10 and 16 were made to donate blood to a company in Gansu province in north-west China.

Reports said the children had been beaten by the gang to make them comply.

Among those arrested was a blood centre official, who told police he had been under pressure to find more donors.

The schoolchildren were reportedly forced to donate once a month for seven months and the amount taken was three times the average amount for voluntary donors.

The gang, who netted 6,250 yuan ($1,000; £600) in the process, presented false identity cards at the blood centre to pretend the children were adults. Under Chinese law, blood donors must be over 18.

The scheme came to light when one of the youngsters sought help from his parents.

The deputy chief of the blood centre and six other men were arrested, according to the official Xinhua news agency.

The company, Lanzhou Institute of Biological Products in the city of Wuwei, is one of the country's biggest producers of blood products, Xinhua said.