Eleven people were shot dead in Cape Verde on Tuesday including eight soldiers, a local civilian and two Spanish citizens, state TV and police sources said.
There were no immediate details of the killings, but authorities were due to hold a press conference.
Cape Verde’s battle against gangs smuggling Latin American cocaine to Europe has led to a series of reprisal shootings, though it was not known whether the killings were drug-related.
The country has worked with Western law enforcement agencies in its fight, including the U.S Drug Enforcement Administration.
Authorities seized 280 kilograms of cocaine earlier this month in a bust in the Atlantic from a Brazil-registered fishing vessel as it prepared to transfer the drugs to a U.S.-flagged yacht.
Cape Verde is an Atlantic archipelago of 500,000 people.