Two people have been arrested on suspicion of attempted murder after three people were attacked with samurai swords at a party in Bolton.
Police officers were called to reports of a fight at a house on Eastwood Close early on Saturday morning.
It is thought there had been a row at the party and a man had left, returning with another man and the swords.
Two of those injured had cuts to their arms and legs and are being treated in hospital.
Their injuries are not thought to be life-threatening.
Two men aged 28 and 30 have been arrested and are being questioned by police.
Det Insp Andy Cunliffe said: "This is an isolated and very rare incident and I would like to reassure those living in the area that a dedicated team are working solely on it."
Police have stepped up patrols in the area and will be carrying out house-to-house inquiries over the next few days.