By Helen Murphy
BOGOTA (Reuters) - Colombian President Juan Manuel Santos sent troops to patrol the streets of Bogota on Friday after violent protests caused havoc across the capital, killing two people and leaving parts of the city in shambles.
Santos took the measure after almost two weeks of roadblocks, protests and clashes with police that spread from the countryside to cities, including Bogota, Medellin and Cali.
Police fired tear gas in downtown Bogota late on Thursday and a curfew was imposed in three densely populated areas of the capital overnight to control outbreaks of violence and looting.
"Yesterday I ordered the militarization of Bogota and I will do the same in any region or zone where the presence of soldiers is necessary," Santos said after an overnight cabinet meeting, adding that he was making ready as many as 50,000 troops.
"There is no protest, as fair as it may be, that justifies loss of life." the conservative Santos said. "We won't let these vandals get away with this ... Patience has run out."
Troops were posted on street corners in the south of the city on Friday morning, while close to the main square soldiers with rifles leant against walls daubed with political graffiti.
"We've been here since 4 a.m.," said one patrolman wearing camouflage fatigues. "There are rumors of an illegal protest in the afternoon; they could come from anywhere."
The protests began as a strike by farmers angry at agricultural and trade policies they say have left them impoverished, and then spread to other sectors. Bogota, a city of almost 8 million people, has not seen a large military presence for at least a decade, when drug traffickers sought to pressure the government with bomb attacks.
The protests are the fiercest challenge yet to Santos, who took office in 2010 vowing to cut poverty while continuing the free-market policies that have boosted foreign investment, especially in mining and oil.
How he handles the street turmoil may now play a big part in whether he seeks a second term next year.
Santos is already under pressure after taking a political gamble to open peace talks in Cuba with Marxist guerrillas of the Revolutionary Armed Forces of Colombia, or FARC.
Santos' government has said the rebels infiltrated the protests in an attempt to create disorder and put pressure on Santos at the negotiating table to get what they want.
While Colombians are desperate to see an end to five decades of conflict, many are losing patience after almost 10 months of difficult talks that have brought just partial agreement on one of five agenda points.
"He should have met the farmers from the first day, dialogue was necessary," said Pedro Pablo Pardo, a 38-year old security guard in Bogota who believes the FARC is behind the violence.
"Farmers don't smash business windows and hurl stones."
The FARC has increased its political sway in many rural areas since the peace talks kicked off in Havana in November, offering its backing to rural and labor movements.
Farm leaders on Friday rejected the violence and said they had reached partial agreement with the government which would allow them to lift roadblocks.
Thousands of farmers and state workers marched through Bogota and other cities on Thursday, banging pots and pans as they converged after 11 days of blocking roads across the nation to prevent trucks reaching markets.
The protesters were mostly peaceful with many dressed in typical farmer attire of woolen ponchos and brimmed hats.
Then hundreds of masked activists rushed Bogota's main square and pelted shop and bank windows with rocks, smashed bus stops and clashed with riot police who fired tear gas to disperse them.
Santos had tried to ease tension earlier on Thursday, acknowledging that the agriculture sector had been "abandoned." But he called for peaceful dissent while talks about possible solutions continued.
The military will deliver food supplies by air and road to cities that are running low because of the roadblocks, Santos said. Food prices have shot up in some places due to shortages.
The demonstrations are the second wave of national strikes this year against agricultural and economic policies.
"This is getting totally out of control. This was purely rural and now it has shifted to an urban problem," said Alfredo Rangel, a security analyst. "I think we can expect to see more of this as it gets closer to elections."
Farmers complain that life has become harder in recent years because income from harvests has failed to cover costs of fertilizers and transportation.
Potato, corn and milk producers say free trade agreements with Europe and the United States have made it almost impossible to compete with cheaper imports.
A series of droughts followed by unusually heavy rains has also made farming conditions difficult in recent years.
(Additional reporting by Peter Murphy, Fernando Peinado and Luis Jaime Acosta; Editing by Daniel Wallis and Jackie Frank)