A man in a balaclava forced his way into the home of a 77-year-old woman and attacked her, Sussex Police said.
The force said: “Police are appealing for witnesses after a 77-year-old woman was assaulted in her own home by an unknown suspect.
“A man wearing a balaclava forced entry to the premises, in Ravenscroft, Storrington, at about 9.45pm on Friday 16 May.
“He then assaulted the occupant, leaving her with facial injuries, before making off from the scene.
“It is unknown what his intention was. However, police are urging anyone who saw any suspicious activity in the area around that time or captured any video footage to come forward.
“You can report it online or call 101, quoting crime reference 47250093894.
“A 39-year-old man, from Storrington, was arrested on suspicion of assault and criminal damage and has been bailed with conditions until Saturday 19 July as inquiries continue.”