Venezuela is heading for further chaos as competing pro- and anti-government marches consumed the capital, Caracas, and opposition leader Leopoldo Lopez, sought by the authorities on charges ranging from murder to terrorism, turned himself in for arrest.
The death toll from over a week of turmoil had risen to four. Opposition sources said a 17-year-old student protester was killed on Monday when an unidentified vehicle struck him during protests in the state of Sucre. Three others were killed last Wednesday when protests called by Lopez erupted in violence.
Before his arrest, Mr Lopez, a Harvard graduate and hard-line firebrand who heads the Popular Will Party, addressed thousands of supporters who had gathered in white T-shirts and some with makeshift gas-masks made of plastic bottles and tape, as they prepared to march on the Justice and Interior Ministry.
"This is the first step in the construction of the road for change and it must, by necessity, be a peaceful process," he said. "If this imprisonment serves to wake up the people - to definitively wake up the majority of the Venezuelans that want change and want to build that change in peace and democracy, then this wretched jailing will be worth it."
After speaking, Mr Lopez, who had been flanked by other leaders of his party, left the platform and walked to a nearby barrier where he was bundled by police into a vehicle without incident. But by afternoon tens of thousands of supporters had jammed the capital's streets in response to his arrest, paralysing traffic and presenting a new challenge to the government.
Meanwhile a huge crowd of Chavista pro-government protesters, some state oil workers bussed in from around the country, gathered in a central plaza of the city, dressed all in red in support of President Nicolas Maduro. Mr Lopez had earlier rerouted his march to avoid the two sides clashing on the streets. Addressing the rally, President Maduro, who this week ordered the ejection of three US consulate staff accusing them of fomenting unrest in the universities, said he wouldn't succumb to "psychological warfare" and vowed that Mr Lopez should pay for his "treasonous acts". He added: "Nobody has the right to subject families to street violence by small, armed and hooded groups that today, the 18th of February, wanted to overthrow the government. In Venezuela everyone has full political freedoms."
The US State Department called Maduro's allegations against US diplomats "baseless and false" and urged Maduro to enter "meaningful dialogue" with the opposition. White House spokesman Jay Carney voiced concern that the government was using security forces and armed gangs to break up peaceful protests.
Among those on the streets was Bernardo Sarmiento, an import business owner who says his livelihood is threatened by government economic measures. "I want to see a liberated country," he said. "We are a strong people and we won't stand for a government that abuses its power. We aren't seeking a coup d'état today but we are seeking serious change".
In recent weeks, Mr Lopez, 42, has emerged as a hardline opponent to Mr Maduro openly calling for the removal of his socialist government. His push, mostly through mobilising a series of anti-government protests across the country, has put him at odds with the more moderate opposition wing which has been led by the 2012 presidential opposition candidate, Henrique Capriles, a state governor.
Mr Lopez, a distant descendant of Simon Bolivar, who led the Latin American independence struggle against Spain, has stirred support, mostly from students, accusing Mr Maduro of economic mismanagement amid growing shortages of basic goods and an inflation rate of about 56 per cent. Currency controls are increasingly impeding overseas travel for middle-class Venezuelans and crime rates continue to soar.
Mr Maduro, a former bus driver who won election to succeed Hugo Chavez after he died last year, insists Mr Lopez is behind a "right-wing, fascist" plot to overthrow him. He escalated his anti-American rhetoric, apparently after receiving a call from a US State Department official asking him to release detainees and begin talks with the opposition, allegedly adding that there would be "consequences" if he didn't.
"I do not accept threats from anyone in this world," Mr Maduro said on Sunday, adding that he had sent a reply to the White House. "No force will stop us Bolivarians from making justice. In Venezuela, we are ready to go to the bitter end to defend our independence and peace," said the President.
"We are facing the activation of a political crisis intended to break the society and move the masses that follow the right wing."
The Lopez supporters were met by thick lines of anti-riot police as they began to march down Avenue Francisco de Miranda, named after another of the first liberators of the country. Helicopters hovered above and along the street, and every ledge and window was crammed with onlookers watching the protest.
‘The government issued its arrest warrant for Mr Lopez at the end of last week, charging him with murder stemming from the violence that broke out after last Wednesday's protest marches. Some observers meanwhile argue that Washington’s antipathy to the Maduro government is barely disguised.
"Of course, we all know who the US government supports in Venezuela," Mark Weisbrot, co-director of the Centre for Economic and Policy Research, said. "They don't really try to hide it: there's $5m in the 2014 US federal budget for funding opposition activities inside Venezuela, and this is almost certainly the tip of the iceberg - adding to the hundreds of millions of dollars of overt support over the past 15 years."
The surrender of Mr Lopez, which supporters hope will help focus world attention on the conduct of the Maduro government, may only worsen tensions, particularly if he remains in custody for any length of time.
"I haven't committed any crime," Mr Lopez said in a video released to his supporters before giving himself up. "If there is a decision to legally throw me in jail, I'll submit myself to this persecution."