The latest operation marked at least the sixth such strike by the US military on suspected drug-trafficking boats in the Caribbean. Unlike the previous five, Thursday’s strike was not publicly announced by the administration and appeared to be the first in which not all on board were killed, the report said.

The condition and whereabouts of the surviving crew members remain unclear.

According to CNN, the Trump administration has prepared a classified legal opinion authorizing lethal strikes against an undisclosed list of drug cartels and suspected traffickers.

Since September, US forces have reportedly used missile strikes to destroy at least five suspected smuggling boats operating off the Venezuelan coast.

The latest strike comes amid rising tensions between Washington and Caracas. On Wednesday, President Donald Trump said he was considering expanding operations to target Venezuela-based drug cartels on land.

“We are certainly looking at land now because we’ve got the sea under control,” Trump told reporters in the Oval Office, as quoted by the New York Post. “A lot of Venezuelan drugs come in through the sea, but we’re going to stop them by land also.”