A woman and two men were slashed during a robbery in a house in Doncaster.
South Yorkshire Police said a 20-year-old man was attacked in a house in Lime Tree Walk, Denaby Main, at around 7.50pm on Sunday.
Two men were involved in the attack in which their victim suffered cuts to his face and arm before a gold chain was stolen.
A 39-year-old woman and a 21-year-old man also suffered cuts when they tried to intervene.
Anyone with information should call South Yorkshire Police on 101 or Crimestoppers on 0800 555111.