Venezuela careened towards a showdown yesterday between anti-government protesters and security forces, as the death toll from months of demonstrations against embattled President Nicolas Maduro mounted -- as did international concern about the spiralling violence.

The opposition has called fresh nationwide demonstrations in defiance of a new government ban on rallies ahead of Sunday's controversial vote to elect a body to rewrite the constitution.

Four months of protests against the unpopular leftist Maduro have already claimed 113 lives, according to prosecutors -- eight of them during a two-day general strike that ended Thursday.

Among the dead was a police officer who was shot in the head in the northwestern town of Ejido, prosecutors said yesterday.

Tensions went up a notch on Thursday when Maduro issued a decree banning protests and warning that anyone who marches against his planned election of a "Constituent Assembly" risks up to 10 years in prison.

The opposition coalition, the Democratic Unity Roundtable, shot back on Twitter: "The regime declared we can't demonstrate... We will respond with the TAKING OF VENEZUELA."

It called mass protests for today and tomorrow.

"The whole country must tell the world this Constituent Assembly has no legitimacy," opposition lawmaker Freddy Guevara told a press conference.

Maduro countered by urging the opposition to "abandon the road to insurrection."

He urged immediate dialogue, but signaled he was not backing down. Any talks, he said, should happen "before the election and installation of the Constituent Assembly."

Fears of open civil conflict have prompted thousands of Venezuelans to join an exodus into neighboring Colombia.

International concern has mounted, with the United States, European Union, United Nations and major Latin American nations urging Maduro to halt his plan.

The United States has imposed sanctions on 13 current and former Venezuelan officials to try to force a change -- measures Maduro said were "illegal" and "insolent."

On Thursday, the United States ordered relatives of embassy staff in Caracas to leave the country, and authorized US government employees to leave on a voluntary basis, citing "social unrest, violent crime, and pervasive food and medicine shortages."

Canada warned its nationals against non-essential travel to Venezuela and urged citizens already there to leave.

Venezuela's opposition, which controls the National Assembly, has urged civil disobedience against what it terms Maduro's dictatorship.

It is pushing on with its own strategy of trying to force Maduro from power through early elections.

Some 70 percent of Venezuelans oppose plans for the constituent assembly, according to polling firm Datanalisis.

Skirmishes in the street between supporters of the opposition and the Maduro government have become commonplace.