Guinea Bissau's army on Thursday uncovered a large cache of weapons at the homes of two soldiers arrested for taking part in an attack on army headquarters which the regime has described as a coup bid.

Army chief General Antonio Indjai said he was "staggered" by the quantity of arms found during search operations in the northern suburb of Plack 1, at the homes of the soldiers who admitted to taking part in Monday's attack.

The army seized 30 Kalachnikovs, three rocket-launchers, a machine-gun, six crates of shells, three crates of flamethrowers, eight bulletproof jackets and a variety of ammunition in searches witnessed by AFP.

"I am surprised to see so many weapons which would have been used to destroy our country... I call on government to build secure armories to avoid having thousands of arms circulating outside of appropriate channels of control," Indjai told journalists.

On Monday, Indjai announced that a coup attempt by a group of renegade soldiers who attacked army headquarters had been foiled.

The army said it had arrested controversial navy chief Rear Admiral Jose Americo Bubo Na Tchuto -- whom the United States has branded a drug kingpin -- as the "mastermind" of the coup plot.

Some observers put the mutiny down to a falling out between Indjai and Bubo Na Tchuto.

The two soldiers targeted in the army search were Sergeant Jose Batista Sambe from the navy and Antonio Mario Cabi, a former member of the presidential guard who were both arrested Tuesday.

Sambe told journalists he led a commando unit in Monday's attack which was meant to "seize weapons to overthrow the current leadership of the army".

The two men said they were dissatisfaction with poor salaries and living conditions in the impoverished former Portuguese colony.

Guinea Bissau is notoriously unstable, with a history of coups and army mutinies, and has become a stomping ground for drug cartels which use it as a hub to traffic drugs to Europe.

Two people died on Tuesday in clashes between security forces and alleged mutineers as joint teams of soldiers, police and paramilitary police hunted suspects.