Police believe a pair of youths are responsible for two incidents in which Oxford schoolchildren were threatened with screwdrivers.

In the first, two 14-year-old boys were threatened as they walked along a footpath in Littlemore between Longwall and Oxford Road at about 1.50pm on Thursday.

They were followed by two older youths, aged about 16, who shouted at them before stopping them and threatening them with a screwdriver.

One victim ran off into a shop in Oxford Road but his friend was headbutted and needed treatment for facial bruising at the John Radcliffe Hospital. The attackers went through his school bag and took £3 before heading towards Cowley Road, Littlemore.

Later that day, at 3pm a 14-year-old boy was approached by two youths and threatened with a screwdriver between Cricket Road and Iffley Road. However, he managed to run off and nothing was taken.

Police believe the same two youths could be responsible.

The first was about 5ft 8ins tall, with short dark blonde hair, wearing a dark blue hooded top. The second was 5ft 6ins tall, with lighter blonde hair.

Dick Evans, of Oxford police robbery team, said: "These robberies may be connected as the same sort of weapon was used in each case. The incidents would have been frightening for the schoolchildren involved, who were picked on and threatened by older youths."

Anyone with information should call Oxford police on 08458 505505, or Crimestoppers on 0800 555111.