The US military said it killed two people in a strike on a vessel in the eastern Pacific Ocean on Monday, claiming the targets were involved in “narco-trafficking operations”.

The announcement, like most of the military’s statements on the dozens of strikes it has conducted in the eastern Pacific and Caribbean Sea, did not provide evidence to support its claims that the targets were engaged in narco-trafficking.

The US Southern Command said in a social media post that the “vessel was transiting along known narco-trafficking routes” and alleged that the vessel was operated by “designated terrorist organizations”. The statement described the two people killed as “male narco-terrorists”, and did not provide further detail on their identities.

The US Southern Command, which oversees military operations in Latin America and the Caribbean, said it was “applying total systemic friction on the cartels” and said no US military forces were harmed in the operation. The post included grainy video showing the explosion of a vessel from above.

The lethal strike came one day after the military said it had blown up two boats it alleged were smuggling drugs in the eastern Pacific, with explosions that killed five people and left one survivor. The military said the US coast guard activated a search and rescue system for the survivor. The military also shared footage of that explosion and did not provide evidence to support its claims.

The military has killed at least 170 in boat strikes since the Trump administration began targeting vessels in the region in early September, according to the Associated Press.

The US government has faced widespread scrutiny over the strikes, with critics arguing it was illegal under US and international law to kill civilians suspected of crimes.

In December, Democratic senator Adam Schiff called on Pete Hegseth, the defense secretary, to resign over the boat strikes, which the senator said were unlawful and unauthorized.

In January, civil rights lawyers filed a federal lawsuit against the US government on behalf of the families of two men killed in an airstrike on a small boat in the Caribbean on 14 October. The men were from a fishing village in Trinidad and were returning from Trinidad to Venezuela when they were killed.

The suit said the “premeditated and intentional killings lack any plausible legal justification”, saying the strike was “simply murder, ordered at the highest levels of government and obeyed by military officers in the chain of command”.

The administration has argued the strikes are lawful under the rules of war, saying the US is in an armed conflict with traffickers, but legal experts have rejected that rationale.