Thousands of demonstrators marched on Saturday in the Venezuelan capital Caracas against what they see as President Nicolas Maduro's heavy-handed repression of dissent.

At least 31 people have been killed in more than six weeks of student-led protests against the government, representing the biggest challenge yet to Maduro, the elected socialist heir to longtime late president Hugo Chavez.

The Organization of American States decided Friday to close to the press a session at which a prominent Venezuelan opposition lawmaker was expected to speak to the regional body.

The OAS's permanent council voted 22 to 11 in favor of barring the press, with member abstaining.

Demonstrators clashed with riot police in Caracas on Thursday after a march against the arrest of two opposition mayors accused of failing to stop violence in protests that have rocked Venezuela.

Some 3,000 people had rallied against the socialist government of President Nicolas Maduro before a subgroup of protesters threw rocks at police who responded with tear gas and water cannons.

Venezuela upped pressure on the opposition Wednesday after weeks of protests, arresting the mayor of the town where they started and seeking a probe of a prominent anti-government lawmaker.

Authorities said the death toll from the protests rose to at least 30 after a policeman died trying to break up a protest in the western city of San Cristobal, where the demos began February 4.

Venezuela's authorities deployed hundreds of security forces into an opposition stronghold early Monday to stamp out protests in Caracas against the leftist government of President Nicolas Maduro.

The show of force came as the death toll from a month and a half of protests rose to 29 Monday, after a National Guard captain shot one day earlier during a protest in the city of Maracay died.

Anti-government demonstrators clashed for almost two hours Saturday with riot police who finally subdued them after President Nicolas Maduro's security forces cracked down.

Venezuela has seen almost daily anti-government demonstrations over violent crime, shortages of essential goods such as toilet paper, and soaring inflation, in the most serious challenge yet for Maduro since he succeeded late socialist-populist Hugo Chavez last year.

Several hundred supporters of the Venezuelan government staged a colorful rally in the capital Caracas on Saturday, as opponents called for more protests against President Nicolas Maduro and his leftist administration.

Venezuela has seen almost daily anti-government demonstrations over violent crime, shortages of essential goods such as toilet paper, and inflation, in the most serious challenge yet for Maduro since succeeding the late socialist-populist Hugo Chavez last year.

The United States on Friday brushed aside "absurd" accusations by Venezuelan President Nicolas Maduro that it was meddling in the country's internal affairs by intervening in anti-government protests.

Venezuela's Foreign Minister Elias Jaua had earlier called top U.S. diplomat John Kerry a "murderer of the Venezuelan people," accusing him of encouraging the protests that have killed 28 people in five weeks.

A total of 28 people have been killed and 365 injured in anti-government protests rocking Venezuela, the country's top prosecutor said Thursday, lamenting an atmosphere of "violence and chaos."

"In all there have been 28 deaths" since the protests first erupted in early February, Luisa Ortega Diaz said on the sidelines of the U.N.'s Human Rights Council in Geneva.

Three more people were killed in protest-hit Venezuela's north Wednesday, as police fired tear gas and water cannon to push back scores of rock-hurling students in the capital.

About 3,000 students marched in Caracas to mark a month since the first deaths in weeks of anti-government demonstrations that have now killed at least 24 people.