Venezuelan officials said they foiled an early morning attempt by a group of armed “mercenaries” to invade the country in a beach landing using speedboats Sunday, killing eight attackers and arresting two more.

Socialist party chief Diosdado Cabello said that two of the attackers were interrogated by authorities. Cabello said it was carried out by neighboring Colombia with the United States backing the plot to overthrow President Nicolás Maduro – a claim dismissed by U.S. and Colombian officials.

“Those who assume they can attack the institutional framework in Venezuela will have to assume the consequences of their action,” said Cabello, adding that one of the detained claimed to be an agent of the U.S. Drug Enforcement Administration.

Authorities said they found Peruvian documents, high-caliber weapons, satellite phones, uniforms and helmets adorned with the U.S. flag.

Both Colombia and the United States have repeatedly denied previous Venezuelan allegations of backing military plots against the socialist government.

“We have little reason to believe anything that comes out of the former regime,” said a spokesperson with the State Department Bureau of Western Hemisphere Affairs, speaking Sunday on condition of anonymity, referring to Maduro’s government. “The Maduro regime has been consistent in its use of misinformation in order to shift focus from its mismanagement of Venezuela.”

Colombia’s Foreign Affairs Ministry also rejected the claims made by what it called “Maduro’s dictatorial regime.”

Venezuelan Interior Minister Nestor Reverol described the attackers as “mercenary terrorists” bent on destabilizing Venezuela’s institutions and creating “chaos.” Officials said the attack took place on a beach in La Guaira, about 20 miles (32 kilometers) from Caracas and home to the nation’s largest airport.

Authorities say the attackers had vehicles and heavy arms waiting for them in the port city.

Venezuela has been in a deepening political and economic crisis in recent years under Maduro’s rule. Crumbling public services such as running water, electricity and medical care has driven nearly 5 million to migrate.

A coalition of nearly 60 nations backs opposition leader Juan Guaidó as Venezuela’s legitimate leader, saying Maduro’s 2018 election was a sham because the most popular opposition candidates were banned from running.

The United States has led a campaign to oust Maduro, increasing pressure in recent weeks by indicting the socialist leader as a narco-trafficker and offering a $15 million reward for his arrest. The U.S. also has increased stiff sanctions, cutting off Venezuela’s oil sector to choke Maduro from a key source of hard cash.

Iván Simonovis, a former high-ranking Venezuelan police official who now advises opposition leaders on intelligence strategy from Washington, speculated on Twitter that there might have been a clash between security forces on Sunday and suggested Maduro’s government created the story of a plot to justify “repression against the interim government and any Venezuelan who opposes the dictatorship.”

But in addition to U.S. economic and diplomatic pressure, Maduro’s government has faced several small-scale military threats, including an attempt to assassinate Maduro with a drone and Guaidó’s call for a military uprising, which was joined by few soldiers.

The Associated Press reported on Friday that an apparently ill-funded attempt to amass an invasion force of 300 men in Colombia involving a former Venezuelan military officer and an ex-Green Beret, suffered setbacks in March when a main organizer was arrested, an arms cache was seized and some participants abandoned its camps.

Jordan Goudreau, the ex-Green Beret, said in a video posted Sunday on Twitter from undisclosed location that forces had entered Venezuela from other points and were “deep inside Caracas.” He didn’t take credit for the alleged pre-dawn beach invasion, but said “our units have been activated,” although no other signs of unrest surfaced throughout the day.

Retired Venezuelan National Guard Capt. Javier Nieto Quintero appeared in the video with Goudreau, urging members of the armed forces to help liberate the nation in an action he called “Operation Gideon.”

Nieto, when contacted by AP on a Miami telephone, declined to comment and hung up. Goudreau also declined to comment in a call from Caracas.

Cabello linked Sunday’s attack to key players in that alleged plot. One of the men he said was killed, a man nicknamed “the Panther,” had been identified as involved in obtaining weapons for the force in Colombia.

Maduro and his allies say the Trump administration is determined to end Venezuela’s socialist government to exploit the South American nation’s vast underground oil reserves. Maduro remains in power, backed by the military and with international support from Cuba, Russia, China and Iran.

Defense Minister Vladimir Padrino López, speaking on state TV Sunday backed by armed soldiers and tanks units, called the attackers mercenaries who “don’t have souls. They’re cowards.”

Guaidó accused Maduro’s government of seizing on this example of unrest to draw the world’s attention away from embarrassing bloodshed in other parts of the country, including a prison riot days earlier that left at least 40 dead.

“Of course, there are patriotic members of the military willing to fight for Venezuela,” Guaidó said. “But it’s clear that what happened in Vargas is another distraction ploy.”