Eastern Cape police have so far recovered 19 mortars from the Strelitzia Dam in Uitenhage.
Fifteen of the projectiles were recovered by the police’s bomb disposal unit on Monday.
The discovery on Monday came after four other bombs were found by local residents in the dam. They were easily visible because of low water levels.
All 19 bombs, which were live, were deactivated by members of the bomb disposal unit.
The police have since warned residents not to pick up any suspicious objects that they find in or near the dam.
Eastern Cape police spokesperson Brigadier Tembinkosi Kinana said they launched an operation on Monday when more live explosives were recovered.
Kinana added it was up to the local municipality to close the dam to prevent injuries.
“It is up to them to determine if the dam should be closed or not. As the police, we can’t say the dam must be closed off. All we are promising is that we will, from time to time, continue visiting the dam searching for more bombs.”
Kinana said a passer-by found a mortar in the dam two weeks ago and alerted the police. On Friday, two other mortars were found while a third one was discovered on Saturday.
The police earlier said the mortars did not belong to the South African National Defence Force.
Kinana added they were investigating their origin and how they ended up in the dam.
“We don’t know where they came from and how long they have been in the water for. At the moment, we can’t speculate and our investigations are continuing,” he said.