Eight teenagers have been arrested in connection with an assault in Derby in which a stun gun was reportedly seen.
An 18-year-old man was attacked by a group of youths in the Morledge at about 1600 GMT on Monday. He suffered facial injuries.
Officers arrested seven of the eight youths on a bus in Ripley on Tuesday. The eighth was later arrested at an address in Derby.
Two youths aged 18, one aged 17, three aged 16 and two aged 15 are in custody.