Explosives experts have defused four grenades discovered in a house in Groningen during renovation work, reports the Telegraaf.

More than 30 homes were evacuated on Tuesday after workmen discovered the grenades in a plastic bag hidden above the ceiling in an apartment in Adriaan Pauwstraat. ‘When they were removing a ceiling tile, a plastic bag fell down and this seems to have been where the grenades were,’ a police spokesperson told the Telegraaf.

They put them out with other rubble in a wheelbarrow but on discovering that they were explosives, alerted the authorities, who cleared the area.

Police have not spoken to the apartment owner but said he had lived there for many years and possibly did not know of the grenades. They are not – as first reported – thought to date from the Second World War.