Washington DC - The US military conducted a follow-up strike on a boat in the Caribbean that it believed to be ferrying drugs, killing survivors of an initial missile attack, media reported Friday.

Prior to the operation, the troops had been given a directive from US Defense Secretary Pete Hegseth to kill everyone on board, the Washington Post reported, citing unnamed sources familiar with the operation.

"The order was to kill everybody," one of the sources told the Post.

The alleged incident occurred on September 2 during the first publicized strike in a series of attacks against boats in both the Caribbean and eastern Pacific that Washington claims were trafficking drugs in international waters.

Pete Hegseth Hegseth "does not know" who US military is killing in its boat strikes, report alleges

President Donald Trump's administration has not offered evidence to back up the allegations behind its campaign, which has killed at least 83 people, according to an AFP tally of publicly released figures.

On September 2, the US military saw two survivors of an initial strike clinging to the burning vessel, then proceeded to strike them again, the Washington Post reported.

After the September 2 strike, protocols were changed to rescue any survivors, the Post added.

According to CNN, it was not clear whether Hegseth knew there were survivors before the second strike was carried out.

The Intercept initially reported on the follow-up attack on September 10.

On Friday, Hegseth posted on social media that "current operations in the Caribbean are lawful under both US and international law," responding to what he called "fake news," though he did not specifically mention the September operation.

The US Justice Department has defended the strikes as consistent with the law of armed conflict, and the government has signaled it will continue the operations.