An 18-year-old is seriously ill after he was stabbed in a "targeted" attack at his Merseyside home.
Police said the man was in the house on Birbeck Road in Kirkby when four men burst in at about 19:00 BST on Sunday and attacked him.
He was taken to hospital where his condition is described as serious.
The house has been sealed off for forensic examination, house-to-house enquiries are under way and officers are reviewing CCTV from the area.
Det Insp John Webster said: "This was clearly a targeted attack against a man in his own home and I would appeal to anyone who may have seen these men or anything suspicious to contact our officers.
"This was a warm, bright evening and there will have been many people out and about.
"I would like to reassure local residents that there will be an increased police presence in the area, and we are determined to find those responsible."