Police in the Cape Verde islands have found eleven people shot dead at a military barracks. They suspect a missing soldier of carrying out the attack.
The dead included eight soldiers and three civilians, two of which were Spanish citizens, according to local sources.
The barracks housed soldiers protecting a hilltop communications hub. Civilians were reportedly working on repairs there.
The government has placed security forces on red alert at the international airport in Praia, the capital, and at the island's ports.
"Eleven people have lost their lives," a statement by the government said. "The victims were all male, aged between 20 and 51.
"A soldier who worked in the military center has been reported missing and there are strong indications that he carried out this attack."
A policeman reportedly came across the bodies around midday Tuesday, Cape Verde Television said. Police later found an abandoned car containing eight Kalashnikovs and ammunition.
The Cape Verde archipelago, about 600 kilometers (370 miles) off the Senegal coast, is made up of 10 islands, with around 500,000 inhabitants.
The country has recently been fighting international drug rings attempting to smuggle cocaine into the country.
Police last week seized 280 kilograms (600 pounds) of cocaine from a yacht, and officials have linked two recent armed attacks against public figures to that battle.