• Security forces and protesters clashed in parts of the Venezuelan capital of Caracas, shortly after President Nicolas Maduro claimed victory in a disputed election result.
• Photos published by Getty Images showed what appeared to be riot police using tear gas against protesters in Caracas, demonstrators banging pots and pans, along with tires burning on the highway.
• Opponents of Maduro's government could also be seen carrying a large banner that read: "Venezuela, I want you to be free."

Security forces and protesters clashed in parts of the Venezuelan capital of Caracas, shortly after President Nicolas Maduro claimed victory in a disputed election result.

Thousands of protesters took to the streets on Monday to repudiate Maduro's claim of clinching a third six-year term in power.

Photos published by Getty Images showed what appeared to be riot police using tear gas against protesters in Caracas, demonstrators banging pots and pans, along with tires burning on the highway.

Opponents of Maduro's government could also be seen carrying a large banner that read: "Venezuela, I want you to be free."

CNBC could not independently verify the images.

The National Electoral Council, which is loyal to Maduro's ruling party, declared on Monday that the incumbent president was the winner of Sunday's presidential election and had secured just over half (51%) of the votes.

Independent exit polls, however, have suggested a sizable victory for opposition candidate Edmundo González Urrutia.

González and opposition leader Marina Corina Machado, who was barred from running in the election, told supporters on Monday that they had received more than 70% of the vote in the Sunday election.

Machado has called on Maduro to accept that his 11 years in power have now come to an end and rejected the president's claim that his victory is "irreversible."

"He should understand that he was defeated," Machado told The Guardian in an interview published on Tuesday. "I would say his departure is irreversible."

Speaking in a televised address to the nation, Maduro on Monday accused the opposition of stoking what he described as a "political crisis."

"We have never been moved by hatred. On the contrary, we have always been victims of the powerful," Maduro said, according to The Associated Press. "An attempt is being made to impose a coup d'état in Venezuela again of a fascist and counterrevolutionary nature."

'Serious concerns'

The U.S. has expressed "serious concerns" that the publicized election results do not reflect the will and votes of the Venezuelan people.

The White House has called on Venezuela's election officials to publish the full, detailed tabulation of the results.

"We're going to hold judgment until that time," said John Kirby, White House national security spokesperson. "We and the international community are watching, and we will respond accordingly."

Venezuela, which sits atop the world's largest proven oil reserves, has been gripped by a profound years-long political and socioeconomic crisis.

In the last decade, more than 7.7 million people are estimated to have left the country in search of better prospects, reflecting the largest exodus in Latin America's recent history and one of the biggest displacement crises in the world.

The United Nations refugee agency says that approximately 20% of the country's population has fled the country since 2014, citing rampant violence, gang warfare, soaring inflation, as well as shortages of food, medicine and essential services.