An explosion heard in the Holt area last night was caused by a controlled blast of two three-inch mortars by an RAF bomb squad on the Holt Lowes heathland near Edgefield.

Norfolk police were remaining tight-lipped as to the exact details last night, confirming only that 'unexploded ordnance' had been dealt with.

But it is believed the bomb squad were called after the mortars had been found by children using a metal detector.

Lowes trustee and local district councillor Philip High said the 25-acre area of heathland next to the country park was used as a military training area after the last war, and there had been earlier incidents of ordnance being turned up.

'There used to be old tanks on there when we played there as boys,' he recalled.

Clearance work at the site, which has been removing trees to restore the heathland over the past five years, had recently involved the removal of topsoil which could have unearthed another.

Secretary of the Lowes' trustees Simon Harrap confirmed the night's drama, and that police attended to keep people clear of the controlled explosion, but insisted the incident was not a big surprise.

'The guy from the RAF told me he had been called out earlier this year to almost the exact same place,' Mr Harrap said.

'He thinks it's pretty safe though, they were very corroded and old so the chances of them doing any harm are very slim.

'Over the years a few of these have been found but it is normally the tail fins, which are basically harmless pieces of iron.

'With the conservation work turning up the soil recently, we may find a few more if there is some rain. So if anyone does they should phone the police and not touch them.'

Do you know the children who found the mortars? Call reporter David Freezer on 01603 772418 or email david.freezer@archant.co.uk