Colombian President Gustavo Petro has accused the US of committing “murder” after striking what President Donald Trump has called a “drug-carrying submarine”.

Writing on social media, Trump said two people were killed in the US attack on the vessel, which he said US intelligence confirmed was “loaded up with mostly Fentanyl, and other illegal narcotics”.

Petro responded on X, saying: “The Colombian boat was adrift and had its distress signal up due to an engine failure,” when it was struck. He added: “We await explanations from the US government.”

Thursday’s attack is at least the sixth US strike on ships in the Caribbean Sea in recent weeks. It is the first time survivors have been reported.

Trump has defended the ongoing boat attacks, saying they are aimed at stemming the flow of drugs from Latin America into the US, but his government has not provided evidence or details about the identities of the vessels or those on board.

UN-appointed human rights experts have described the US strikes as “extrajudicial executions”.

At least 27 people were killed in the prior five boat strikes in the waters off Venezuela, according to figures released by the US administration.

Trump wrote on his Truth Social platform on Friday that the submarine targeted in the latest attack was “built specifically for the transportation of massive amounts of drugs”.

“This was not an innocent group of people. I don’t know too many people who have submarines, and that was an attack on a drug-carrying, loaded submarine,” he said, adding that no US military personnel had been injured.

The US president also said two people who survived would be returned to their countries of origin, Ecuador and Colombia.

Petro confirmed Colombia had received one of the survivors of the attack, saying: “We are glad that he is alive and he will be processed in accordance with the laws.”

The two survivors were rescued by a US military helicopter and then shuttled onto a US warship in the Caribbean, unnamed US officials told US media earlier.

In recent weeks, Trump has ramped up threats against Venezuela’s leadership over claims that the country is sending drugs to the US. Venezuelan President Nicolás Maduro has accused Trump of trying to make the South American nation “an American colony”.

Trump earlier told reporters that he had authorised the CIA to conduct covert operations in Venezuela, and that he was considering launching attacks on Venezuelan soil.

Narco-subs have become a popular way to transport drugs as they can go largely undetected, and can be sunk after delivery. They are often homemade and constructed using fibreglass and plywood.

The US, as well as other coastal nations, have previously intercepted some of these subs.