A 41-year-old man is in hospital after he was pushed off a balcony by youths who broke into his home.
He was asleep in the property in Ainsdale Drive, Preston, when five youths broke in at about 2230 BST on Friday.
They then pushed him off the balcony before making their escape.
The victim suffered a broken arm and was kept in hospital overnight.
Lancashire Police said it believed the motive of the attack was robbery, although nothing was taken.
Detectives also believe the victim knew his attackers.