Police said the arrested boys, aged 10 and 11, had been arrested on suspicion of assault and would be held overnight for further questioning on Monday.

Reports on Monday said two children - one which was 'hit with a brick and flung down an embankment' and the other 'slashed from head to toe with a knife' - were the suspects victims.

The injured boys aged 11 and 9 were riding their bikes in a park in Edlington, South Yorkshire when they were confronted by two other children aged just 10 and 11 reported ninemsn.com.au.

According to the Daily Mail the boys demanded the pair hand over their mobile phones, money and shoes. When they refused they were allegedly tortured with burning cigarettes, cut with a knife and beaten with bricks.

The 11-year-old victim was found partially conscious at the bottom of a steep slope in Edlington, near Doncaster, and was taken to Sheffield Children's Hospital, where he was put into intensive care.

His condition was described as 'critical but stable' and was showing improvement, police said.

Local resident Jean Wright told the BBC she had raised the alarm after her husband saw the nine-year-old boy walking past their house covered in blood.

'He had a big gash on his arm and he was covered in blood on his head. He was shaking very badly and going into shock,' she said.

The nine-year old was taken to Doncaster Royal Infirmary for an operation on his arm and was expected to have further surgery, police said. -- Reuters