An elderly man has been left shaken after fending off an attacker trying to climb through his window.

The 79-year-old was watching TV alone in his Camberley flat on Monday night, when three males wearing bandanas across their faces knocked on the door and demanded money.

The group were carrying a baseball bat and a knife and one tried to climb through a window.

Detective Glen Yule said the elderly man managed to hit the offender over the head with a heavy object before they smashed a window and fled.

"It's particularly concerning that this gentleman is seventy-nine and these people have come along and picked on him," he said.

"He's got no injuries but he's pretty shaken up by the whole thing."

Yule said they're looking for sightings of a Blue Honda Civic parking outside the Takapu Road house, with about five males inside and are appealing to people if they have "a male family member [who] has turned up at home and they've got a bruise on their head or some sort of injury, then we'd like to know about that."