The National Intelligence and Security Agency (NISA) reported that the military equipment found in a bunker in the district of Huriwa included, among other means of warfare, mortar shells and bomb-making drums.
The agency also indicated in a document that during the mission it arrested three Al-Shabab militants, who will appear in court for trial.
NISA forces have recently seized a large quantity of weapons from the extremist group in hidden caches, including one recently detected in the town of Elasha Biya, south of Mogadishu, the report said.
On the 25th of this month, a car bomb attack in the capital, claimed by Al- Shabab, killed eight people and wounded 17.
The bloody attack was condemned by various organizations, including the United Nations and the Intergovernmental Authority on East African Development, which is made up of eight countries in the sub-region.