Champaign and University of Illinois police are urging people to travel in pairs following a string of attacks on campus.

According to reports, Champaign Police Lt. Jim Clark said Monday the two departments are working together to implement crime prevention strategies. He says there have been 12 incidents of robbery and "mob action" around campus in the past two weeks.

Clark says police are deploying officers in plain clothes and uniforms to proactively monitor campus activity. They are partnering with the university's student patrol to watch areas where the crimes have occurred.

Police are investigating after a 22-year-old reported being pepper-sprayed and robbed in Champaign on Sunday.

Authorities charged an 18-year-old from Urbana with robbery after a 21-year-old reported being punched in the head and robbed Sunday.