Cuba says it thwarted armed exiles on a Florida-registered speedboat who were trying to infiltrate from the US

A deadly exchange of fire between two boats off the coast of Cuba, killing four and wounding six, has raised already high tensions between Washington and Havana.

Cuba’s government said a US-registered boat was carrying 10 people, most of whom it claimed “have a known history of criminal and violent activity”. The US secretary of state, Marco Rubio, said the US was gathering its own information but called the open sea shootout “highly unusual”.

Here’s what we know so far.

Cuba said its coastguard shot dead four people and injured six others travelling in a US-registered speedboat just after 2pm ET on Wednesday, in an exchange of fire one nautical mile from Cayo Falcones island, off Cuba’s northern coast.