The whole of Thurbern Road, in North End, Portsmouth, was closed off on Saturday at 2pm after 11-year-old Kyle Roberts discovered the grenade in a box of items his dad had bought from a car boot sale.

The Royal Navy bomb disposal squad was called and fortunately it turned out to be a false alarm as they identified the grenade as a training dummy.

Kyle said: 'My dad bought a box and me and my mum were looking in the box and I found something round. I picked it up and I said "dad what's this?" and he said "I think it's a grenade".

'I got all shaky and scared as I know that they are dangerous. I went into the house and I was panicking.'

His dad, Paul Roberts, 40, said: 'When my boy handed me a grenade it was really scary. It looked so real and I started panicking thinking it could go off at any minute. Especially with four kids in the house.

'I put it straight into the drain in the garden, it was the nearest thing to me.'

Police went to the scene and cordoned off the road and stopped residents going in while they investigated the grenade and the other items in the box.

Inspector Howard Lovegrove, of Fratton police station, was at the scene. He said: 'My lads, as always, checked it out.

'We have certain distances we have to keep people at so had to shut the road off. It's an inconvenience for everybody but we have to be safe. Imagine having that in the wrong hands it could cause some alarm.'

Paul Bhathena, a bomb disposal operator at Horsea Island, said: 'It's good that it was brought to our attention because you can never be too careful.

'Somehow it got out of an army base and ended up in a box of different bits and pieces in a house down the road.'