Two people were stabbed and three others were hurt in a fight near a hotel, police say.
A man was stabbed in his head and neck and a woman was stabbed in her arm in Southport at about 06:00 GMT on Saturday.
Two other women sustained bruising to their faces and another man was hurt.
Merseyside Police arrested two women and two men, aged between 21 and 24, from Southport, a woman, 20, from Kirkby and a man, 20, from Lancashire.
They said all the injured people had been discharged from hospital and appealed for anyone with information to contact them.