Under the late elected socialist revolutionary leader Hugo Chavez, Venezuela forged tight ties with Cuba, becoming its closest regional ally and economic mainstay of the Americas' only communist regime.
The close bilateral alliance, which includes military and security cooperation, is still pursued under President Nicolas Maduro's year-old government.
At least 28 people have been killed and 400 injured in the student-led protests that began February 4 in western Venezuela and spread to Caracas and other cities.
Oil-rich Venezuela has seen almost daily anti-government demos as tens of thousands of people vent their rage over the soaring violent crime rate, spiraling inflation and a lack of basic household goods like toilet paper.
More From This Section
Marchers were called out to the streets by the Popular Will, an opposition organization led by Leopoldo Lopez. He has been jailed since February 18.
The chanting throngs, sounding noisy horns, tried to march on the Cuban Embassy to rally.
But authorities blocked them from getting to their target, and demonstrators headed to La Carlota military airfield instead.
The bilateral alliance also includes energy, food, defense and health care.
"We completely reject Cuban involvement in our affairs, of the Castro brothers in our Armed Forces and in our institutions," the university student said.
Some analysts say there are Cuban advisers and Cubans taking part in Venezuela's security. Caracas does not comment on the claims.
Cash-strapped Cuba depends almost entirely on Venezuela's largesse billed as solidarity aid to keep afloat its ailing, Soviet-style centrally managed economy.
Cuba's top hard-currency earning export is the USD 6 billion Havana earns each year from sending its medical staff overseas on government contracts.