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Army ordinance experts detonated a live World War 2 hand grenade in Christchurch today after council contractors unearthed it while excavating a new suburban stormwater drain.
Police cordoned the area in Fairfield Ave, Addington, after the discovery about 9.30am and called in the army and Fire Service personnel.
City Care construction site superviser Allan Baker said the grenade was found about 50mm below the surface and was "very rough and rusty".
Mr Baker said staff stopped work immediately and called police.
Police kept residents well back from the construction site while two members of the army's ordinance disposal squad made a controlled explosion.
Only tiny fragments of the grenade remained after the blast and police said it appeared the grenade was live.
- NZPA