Two teenage boys were attacked while walking in a town centre.
Police say the pair, both aged 14, were assaulted in The Broadway, in Houghton, on Saturday night.
Officers have said they are now working to establish exactly what happened in the incident and have also appealed for any witnesses to come forward.
A spokeswoman for Northumbria Police said: "At 10.36pm on Saturday, August 19, police received a report of an assault.
"Two boys aged 14 were reported to have been attacked in Houghton as they were walking in The Broadway area.
"Neighbourhood officers are making enquiries to establish the circumstances around the incident."
Officers added that anyone with information regarding the assault is asked to contact 101 quoting log 1231 190817 or call Crimestoppers anonymously on 0800 555 111.