America’s armed forces said they carried out another strike on a suspected drug-trafficking vessel in the Caribbean, killing three individuals described by officials as “narco-terrorists”. The operation marks the third such attack in the region this month.

According to military figures, roughly 150 people have been killed in American maritime strikes across the Caribbean and the Pacific since September, a campaign that appears to be expanding in both scope and tempo. Critics question the legal framework underpinning the operations and the intelligence used to identify targets at sea.

The escalation comes as Marco Rubio, America’s secretary of state, prepares to travel to the Caribbean this week for talks centred on regional security and counter-narcotics co-operation.