Interior Minister Nestor Reverol gave no details on the number of people detained or killed in the operation, which he said was still underway, with a massive search on air, land and sea.
Venezuelan officials said they foiled an early morning attempt by a group of armed men to invade the country by boat on Sunday, killing eight attackers and arresting two more.
Socialist party chief Diosdado Cabello said that two of the attackers were being interrogated by authorities.
Cabello said it was carried out by neighbouring Colombia with United States backing in a plot to overthrow President Nicolas Maduro.
Both countries have repeatedly denied earlier Venezuelan allegations of backing for military plots against the socialist government.
"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 US Drug Enforcement Administration.
Authorities said they found Peruvian documents, high-calibre weapons, satellite phones, uniforms and helmets adorned with the US flag.
Interior Minister Nestor Reverol described the attackers as "mercenary terrorists" bent on destabilising Venezuela's institutions and creating "chaos."
Officials said the attack took place on a beach in La Guaira, about 20 miles 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 back opposition leader Juan Guaido 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 narcotrafficker and offering a $15 million reward for his arrest. The US also has increased stiff sanctions, cutting off Venezuela's oil sector to choke Maduro from a key source of hard cash.
In addition to that pressure, Maduro’s government has faced several small-scale military threats, including an attempt to assassinate Maduro with a drone and Guaido’s call for a military uprising, which was joined by few soldiers.
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.
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 the main organiser was arrested, an arms cache was seized and some participants abandoned its camps.
Cabello linked Sunday's attack to key players in that alleged plot.
Meanwhile, Cesar Omana, a businessman who participated in an unsuccessful plot against Maduro a year ago, said some 30 armed commandos from the Sebin intelligence police raided his Caracas home early Sunday.
Omana is not in the country.