(Recasts with search for Lopez)
By Andrew Cawthorne and Daniel Wallis
CARACAS, Feb 13 (Reuters) - Venezuelan authorities sought on Thursday to arrest an opposition leader who has been organizing street protests that led to three deaths in the worst unrest since President Nicolas Maduro's disputed election victory last year.
A judge's arrest warrant, published in local media, said the 42-year-old hardline politician was wanted on charges ranging from instigating crime to murder and terrorism.
Members of his Popular Will party acknowledged there was a warrant for Lopez's arrest but would not say where he was.
Lopez, who lives in the wealthy Chacao district of Caracas where he was once mayor, accuses Maduro's government of making him a scapegoat for state-led violence against protesters.
Almost a year after the death of socialist leader Hugo Chavez, the bloodshed on Wednesday in the capital Caracas was the latest demonstration of the OPEC nation's deep polarization and the mutual mistrust between both political camps.
Three people were shot dead after pro- and anti-government marches in Caracas. Maduro said another person was in critical condition, and he blamed "small fascist groups" that he said infiltrated the opposition protest.
Further protests would not be allowed, he said.
"They want to topple the government through violence," Maduro said on state television. "They have no ethics, no morals ... We will not permit any more attacks."
Some 23 people were injured, 25 arrested, four police vehicles torched and some government offices vandalized, officials said. Some opposition protesters, many with their faces covered, threw stones and burned tires in the streets.
On Thursday, the streets of Caracas were quieter than usual, with some residents staying at home and a heavy police and military presence. But there were no reports of new trouble.
LOPEZ: "I'M INNOCENT"
Using the slogan "The Exit", meaning Maduro's departure from power, hardline opposition groups have been holding mostly small protests around the country for the last two weeks, complaining about crime, corruption and the fast-rising cost of living.
U.S.-educated Lopez, who has been calling supporters to take to the streets for two weeks, said the government planned Wednesday's bloodshed to try to discredit his peaceful movement.
"The government is playing the violence card, and not for the first time," he told Reuters after the shootings.
"They're blaming me without any proof ... I'm innocent. I have a clear conscience because we called for peace," he said, adding that the demonstrations would continue.
"We won't retreat and we can't retreat because this is about our future, about our children, about millions of people."
The protests have exposed differences within the opposition's leadership, with some favoring a more moderate approach and saying marches which turn violent only play into the government's hands as it accuses them of being "saboteurs."
Maduro, a 51-year-old former bus driver and union activist, has staked his presidency on maintaining Chavez's leftist legacy.
He says opposition extremists want to recreate the situation in 2002, when huge street protests led to a coup that briefly ousted Chavez. He returned to power with the help of loyal soldiers and hundreds of thousands of "Chavistas" who took to the streets to protest the coup.
There have been no signs that the current melees could topple Maduro.
The opposition blames armed pro-government militant groups known as "colectivos" for attacking dozens of their marches over the years, scattering their supporters and spreading fear.
"The colectivos are coming!" was a cry heard several times at the opposition's latest rally on Wednesday, prompting some demonstrators to flee for the safety of a nearby Metro station.
One of the dead was a well-known colectivo leader from the militantly "Chavista" January 23 neighborhood of Caracas.
Two spokesmen for the colectivos appeared on state TV late on Wednesday to call for calm and demand Lopez face charges.
Sporadic political protests have become common over the last decade, but they usually fizzle out within days as residents grow tired of blocked streets and the smell of burning tires.
Wednesday's outburst of violence could point to a widening rift between opposition hardliners and those who favor returning to addressing bread-and-butter issues such as poor services, widespread corruption and one of the world's worst murder rates.
Opposition moderates note that their biggest successes, such as turning pro-Chavez strongholds into opposition territory, have resulted from leaders stepping away from theatrical street protests to focus on voters' daily concerns.
"For the moment, the protests do not pose a short-term threat to President Maduro's ability to stay in power," said Venezuelan political analyst Diego Moya-Ocampos. (Additional reporting by Caracas bureau reporters, Javier Lopez in Tachira Editing by W Simon)