Police have stepped up patrols around the University of York after a student was robbed and another hit in the face.
A 21-year-old man was on Walmgate Stray on Monday night when he was threatened by four people who stole his mobile phone, wallet and cigarettes.
Police said a 21-year-old man, a 16-year-old boy two 15-year-old boys and a 13-year-old girl were arrested.
Another student was on Walmgate Stray on Tuesday when he was hit by two people who tried to steal his property.
He received a gash to his face and was taken to York District Hospital.
As a result of the two incidents, patrols have been increased in the Walmgate Stray area and the University of York campus.
Sgt Andy Haigh said: "I would advise people using Walmgate Stray as a cut through to be extra vigilant, especially after dark."