A man was assaulted during a house party in Oriel Road, Daventry, at the weekend.
The incident happened in the early hours of Sunday, November 8, between 12.30am and 12.50am.
A small group of people, after leaving the party, were in the street being abusive and aggressive.
When challenged, they threw bottles at the victim, resulting in a deep cut that required stitches.
The incident happened in a quiet residential street. Officers believe a number of neighbours will have seen or heard the disturbance and are keen to hear from anyone who may have witnessed the assault or have any information about the offender/s.
Witnesses, or anyone with information, are asked to call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.