The U.S. military continued its assault on what it claims are drug-running boats off the coastal waters of Latin America with another strike Thursday that the Pentagon said killed four people.  

The strike in the Eastern Pacific was ordered by Defense Secretary Pete Hegseth, U.S. Southern Command said in a social media post that included unclassified video of the attack.  

"Intelligence confirmed that the vessel was carrying illicit narcotics and transiting along a known narco-trafficking route in the Eastern Pacific," said U.S. Southern Command, which is responsible for U.S. military operations in the Caribbean Sea, and the waters off Central and South America. "Four male narco-terrorists aboard the vessel were killed."

Since early September, the U.S. military has launched at least 22 strikes on vessels in the Eastern Pacific and the Caribbean that the Trump administration claims, without providing more evidence, are trafficking drugs.

At least 87 people have been killed in the strikes so far. Thursday's was the first known strike since Nov. 15. 

The boat attacks are part of larger efforts by the White House to put pressure on the regime of Venezuelan leader Nicolás Maduro.

It also comes as Hegseth has faced scrutiny in the wake of a recent Washington Post report over a Sept. 2 boat strike in the Caribbean that killed 11 people, the first in the series of vessel attacks.

The report claimed the U.S. military struck the boat with two missiles, a revelation that the White House confirmed. Some lawmakers have questioned whether the second strike constitutes a war crime.

A source familiar with the matter told CBS News on Wednesday that the second strike came as two people who survived the first missile were trying to climb back onto the boat. The survivors were allegedly trying to salvage some of the drugs, according to the source. 

Hegseth has denied that he ordered the second strike, saying that the decision was made by Navy Adm. Frank "Mitch" Bradley, head of Special Operations Command. The Washington Post report also alleged Hegseth had ordered everyone on the boat killed, which he has denied, and which Bradley also denied, lawmakers who were briefed on the strikes told reporters.

On Thursday, congressional lawmakers held a closed-door session during which they were shown video of that second strike and were briefed on the incident by Bradley and Gen. Dan Caine, chairman of the Joint Chiefs of Staff.

After seeing the video, Rep. Jim Himes of Connecticut, the top Democrat on the House Intelligence Committee, called it "one of the most troubling things I've seen in my time in public service."

However, Republican Sen. Tom Cotton of Arkansas, chair of the Senate Intelligence Committee, said he "didn't see anything disturbing about it."