The ordnance is likely to date in its entirety from World War Two, since the island was the scene of heavy fighting, particularly during the Soviet Moonsund Landing Operation in October-November 1944.

Unexploded aerial bombs, artillery shells and other ordnance is regularly found in the region, often lying buried, unexploded, for decades and moving towards the surface through the course of freeze-thaw action and other natural phenomena.

This haul, which so far totals 454 pieces of ordnance such as shells, and nearly 700 cartridges and over 33 kg of World War Two-era ammunition, BNS reports, looks set to grow as the large-scale Rescue Board operation continues through to the end of the week, according to spokespersons.

Rescue Board officials also collected 33 signal flares, used in boating, from residents in Kuivastu harbor, though the precise circumstances of this were not reported. 

In addition to unexploded ordnance used in anger, World War Two ammunition dumps are sometimes found in Estonia, most recently during the construction of the Reidi Road, east of the city centre. The same project also revealed military installations from a much earlier era, when a Crimean War artillery battery was unearthed last summer.