THREE separate gangs are thought to be responsible for a string of attacks on foreign students across Oxford.

We have reported on 18 robberies in the city since July 6 and ten have been on young visitors.

Four attacks on foreign students took place on Monday and police said they would continue to step up patrols across the city.

The latest involved a 14-year-old Taiwanese boy who got off a bus with a friend at The Oval, in Rose Hill, at about 9.15pm on Monday.

They walked towards the shops and were approached by three men, two of whom were carrying iron rods.

The student was pushed to the ground and held down by one of the men while the others ransacked his pockets and took a wallet containing £50 and 800 Taiwanese dollars, worth about £15.

They also took his Sony Ericsson G700 mobile phone.

At 7.40pm on Sunday, a 45-year-old Swedish man and a 46-year-old Swedish woman were approached by a knifeman in Merton Street who demanded their camera and wallet. He fled when they handed him £20.

Ten minutes later, in Magpie Lane, a 17-year-old Swedish youth was robbed of his wallet at knifepoint. Police believe the same man was responsible.

Det Sgt Matt Jarman, of the Oxford robbery team, suggested three separate gangs may be targeting victims in Blackbird Leys, Oxford city centre and Rose Hill.

He said: “They are not all linked.

“For the Blackbird Leys crime series, the descriptions are very similar for most of the offences and the ones in the city centre, have similar descriptions too.

“The one in Rose Hill looks like it was a stand alone job. It looks like three separate groups.

“These visitors come to Oxford because it’s got a good name to study language or they are trying to imerse themselves in the history of the city and this happens. It leaves a bad taste in the mouth.”

Det Sgt Jarman said attacks on foreign students were normal for this time of year, although the numbers were slightly higher than usual.

He said: “They are vulnerable and they stand out a little bit with their cameras and bags. They carry everything that you and me would take on holiday.

“You often find those who commit these offences tend to hunt in packs. You do get individuals, but very often they operate in twos, threes or fours. Luckily, injuries haven’t been that great. Some carry weapons, some don’t.”

Insp Andy Storey, neighbourhood inspector for Rose Hill, said: “We are doing extra high-profile patrols in Blackbird Leys and Greater Leys and we want to expand that to cover Rose Hill. One robbery is too many. ”

Carmel Engin, a director of the Lake School of English in Oxford, said: “We are aware these attacks sometimes take place, but all our students are issued with a 24-hour emergency card and they are given a talk on personal safety.”

Call police on 08458 505505 or Crimestoppers on 0800 555111 if you have information.