Residents were forced to evacuate their homes after a military weapon collector accidentally bought a live Second World War grenade.

The Hungarian stick grenade was advertised as decommissioned, but when it arrived, the device appeared to have explosive powder inside.

Upon the discovery, Kallum Williams, 23, who collects decommissioned military weapons, called the police and waited all night for officers to arrive.

Mr Williams, from Llansantffraid in Powys, Mid Wales, said the grenade should have had holes in it and the powder should have been removed.

He said: “It felt like a salt shaker. We were too nervous to sleep.”

After arriving at the scene, police cordoned off the area and told neighbours to evacuate their homes as a precaution.

An X-ray by an explosive ordnance disposal (EOD) team revealed that there was powder inside the grenade.

The device was taken to a field to be safely detonated. “We heard the explosion,” Mr Williams said.

After contacting the supplier, he said they claimed the grenade had sand inside, but the EOD team found no signs that it had ever been opened.

Mr Williams said he was upset about disturbing his neighbours and wanted to reassure them that nothing in his collection poses a risk to them.

Dyfed-Powys Police said it responded to a call over the suspicion that it was “a live military grenade in his possession”.

A spokesman said: “Officers attended with an explosive ordnance disposal team and the device, a small inert hand grenade, was destroyed in a controlled manner.”

In February, one of the biggest peacetime evacuations in British history took place when an unexploded Second World War bomb was discovered in Plymouth.

Thousands were forced to leave their homes after a half-a-ton explosive dropped by the Luftwaffe 83 years ago was found in the garden of a residential property.

Three days after it was discovered in the Keyham area of the city, the explosive was detonated at sea. The explosive had to be carefully extracted and the operation brought parts of the city to a standstill.

Residents living within 1,000ft of an exclusion zone were evacuated as the bomb was taken on a military convoy along a 1.6-mile route towards a ferry slipway.

The operation was described by the MoD as “one of the largest UK peacetime evacuation operations since the Second World War”.