Venezuela's opposition refused Wednesday to take part in talks that were called by the government in a bid to halt three weeks of protests that have left 14 dead.

"We will not lend ourselves to a sham dialogue that would end in a mockery of our compatriots," the the opposition coalition MUD said in a letter to Vice President Jorge Arreaza.

The United States is expelling three Venezuelan embassy officials in a tit-for-tat move after Caracas kicked out three American diplomats last week, a State Department official said Tuesday.

The three Venezuelans have been given 48 hours to leave the United States, the official said, in a move that came just as Venezuelan President Nicolas Maduro said he was planning to appoint a new ambassador to Washington.

Opposition protesters erected barricades across major thoroughfares on Monday, bringing traffic to a halt in parts of the Venezuelan capital in a continuation of the unrest that has roiled the country for nearly two weeks.

The barricades of trash and other debris prompted the cancellation of some bus routes and made the morning commute a nightmare for many, but there were no reports of major violence as police began dismantling the roadblocks. There were similar reports of blockades in the provincial cities of Maracaibo and Valencia.

Venezuela President Nicolas Maduro is readying crisis talks to try to defuse a deadly wave of protests that have brought the biggest challenge yet to his government.

"This is a national peace conference I am calling for Wednesday with all social, political, union and religious groups," Maduro told supporters outside the presidential palace.

Hundreds of mainly elderly people marched Sunday in downtown Caracas in support of President Nicolas Maduro, a day after Venezuela's largest demonstrations in weeks of escalating protests left 25 people injured.

Maduro is grappling with the biggest crisis of his rule since narrowly being elected last year after the death of leftist icon Hugo Chavez, with at least 10 people dead since protests erupted on February 4.

President Nicolas Maduro said Saturday that remarks by U.S. Secretary of State John Kerry on the unrest in Venezuela gave violent groups a "green light" to carry out attacks.

In a tweet, Maduro also slammed the remarks made by Kerry late Friday as "arrogant" and "insolent."

Venezuelan President Nicolas Maduro urged Barack Obama to "accept the challenge" and hold direct talks, a surprise overture made Friday after days of accusing Washington of plotting his overthrow.

The announcement came after nearly three weeks of often violent anti-government protests in Caracas and other major cities, the biggest test to Maduro since he succeeded leftist icon Hugo Chavez last year.

The United States expressed concern Friday over the jailing of Venezuelan opposition leader Leopoldo Lopez and insisted that any charges against him be handled in an "impartial and transparent" manner.

Lopez has been in custody since his arrest Tuesday amid protests in Caracas and other Venezuelan cities against the leftist government of Nicolas Maduro.

Customs authorities at the Rafik Hariri International Airport foiled two attempts to smuggle 7.5 kilograms of cocaine into the country on Friday.

“Two Turkish citizens were arrested for trying to smuggle the drugs from Venezuela into Lebanon,” NNA said, noting that one of the Turks arrived from France and the other from Abu Dhabi.

The U.S. company whose "walkie-talkie" application Zello has become a wildly popular organizing tool for Venezuelan anti-government protesters says the country's state-run telecom company has just blocked its use.

CEO Bill Moore of the Austin, Texas-based Zello tells The Associated Press that Venezuela's main mobile operator and Internet provider — Movilnet and CANTV — blocked access on Thursday to Zello.com.