Al-Shabab now claims that it was behind the accident in which a boat carrying Somalia National Army capsized off the beach in the town of Marka, killing four people.
But the government maintained that it was an accident. 13 other people were rescued.
18 AK 47 riffles and an assortment of other weaponry were lost during the accident.
The troops opted to travel by water after Al-Shabab imposed a blockade in Marka, 60 miles from Mogadishu, making travel by road risky.
In the recent past the militia group has suffered major casualties in the hands of the SNA and forces in the Southern sector, as over 30 have been killed in the past ten days.