The 45-year-old victim was at home in Cottage Grove, Southsea. He answered a knock at the door between 11am and 11.30am yesterday.

A man holding a black-handled claw hammer came in and began hitting the resident with the weapon.

The attacker hit the man on his head, chest and back before fleeing. The victim was taken to Queen Alexandra Hospital, Cosham, for treatment.

The man suffered cuts on the top and back of his head and has possible broken ribs.

Detective Constable Jo Morris, who is leading the hunt for the attacker, said: 'This was an unprovoked attack where the offender used a claw hammer on the man and then ran away, leaving his victim with head injuries.

'I would appeal to anyone who may have heard or seen anything, or thinks they may have seen a man fitting the description in the area.

'If you have any information which may assist us then please call police as soon as possible.'

Speaking after the incident, shocked residents spoke of their disbelief.

Norma Priestley, 61, has lived in Cottage Grove for 27 years.

She said: 'It is disgraceful, absolutely disgraceful. I live with my mum who is disabled and has dementia. She was on her own today so I dread to think about it. Hopefully the attacked man is not too badly injured. We have had a few break-ins down here but never anything like this.'

Lee Ruttle, 39, also of Cottage Grove, Southsea, said: 'It's a shock. You don't expect it when it's on your doorstep.

'When you get something like this it really does make you worry.

'You don't want to worry every time you open the front door that someone is going to attack you.

'It's really shocking it happened at that time of day, you'd expect plenty of people to be about then.'

Michelle Wickham, 28, of Salisbury Road, Southsea, often babysits for her sister, who lives in Cottage Grove.

She said: 'It's just terrible. It's just too close to home. It makes you frightened and it will make me think twice about walking down the street.'