Somalia's National Security and Intelligence Agency (Nisa) said it seized two shipments of military equipment that were apparently bound for Al-Shabab militant group.
It said the stockpiles were found at Mogadishu's port and airport on Thursday and were linked to "businessmen who had been authorized by the government to import necessary goods".
At the port, the shipment was hidden in commercial goods being imported into the country, the agency said. Four vehicles prepared to transport the equipment to the militant group were also seized.
Investigation relating to the shipments had led to the arrest of 10 people linked to a weapons smuggling network operating locally and abroad, a statement by Nisa said.
""Our agency has been following the activities of these individuals in Somalia and outside Somalia. It has been following their involvement in this smuggling network. Fortunately, all of them are in custody, and none has escaped," Defence Minister Mohamed Ali Haga is quoted as saying by news agencies.
No details were offered on the contents of the seized shipments, their origin or the identities of those involved.
The troubled Horn of Africa nation has witnessed a surge in attacks as government forces and allied militias wage a declared "all-out" war against the al-Qaeda-linked militants.
The army and local militias known as "Macawisley" have retaken chunks of territory in the central Galmudug and Hirshabelle states in an operation backed by US air strikes and an African Union force.
Al Shabab remains entrenched in parts of rural central and southern Somalia.
