SANTIAGO (AP) -- South American presidents agreed Monday to work urgently to prevent a political collapse in Bolivia, where the government said it would charge a rebellious governor with genocide for allegedly ordering the machine-gunning of peasants.

Condemning two weeks of unrest in which Bolivia's leftist president, Evo Morales, effectively lost control of half his country, the leaders demanded protesters immediately vacate seized government offices and ""halt violence and intimidation.""
They accepted Morales' claim that a massacre occurred in the breakaway state of Pando, offering to investigate and agreeing as well to create a commission to try to spur dialogue between Bolivia's government and opposition.
""UNASUR's ability to respond very rapidly to the first situation of this sort and to be capable of building an accord should be recognized,"" President Michelle Bachelet, who hosted the six-hour meeting behind closed doors, told reporters afterward.
Appearing alone on the presidential palace's patio, she read a nine-point statement and took no questions.
The 12-nation Union of South American Nations was only founded in May and the Bolivian crisis, in which anti-Morales protesters have blocked highways, closed border crossings and sabotaged natural gas pipelines, is its first major test. Only the presidents of Peru, Suriname and Guyana did not attend.
Most of the leaders departed without comment but Morales, in brief remarks, said he was ""surprised by the solidarity"" of his colleagues and called it ""the first time in history that we South Americans are deciding to solve the problems of South America.""
Morales has the support of most Bolivians — voters ratified his presidency by an impressive 67 percent in an Aug. 10 recall referendum — a 13 percent jump over what the native Aymara and former coca-growers union leader won in December 2005 presidential elections.
But the same referendum also gave several of the rebellious governors renewed support in their provinces.
Bolivia's chief prosecutor, Mario Uribe, said he would press charges of genocide against Gov. Leopoldo Fernandez and other top officials in Pando, the jungle province on the Brazilian border where at least 15 people were confirmed killed in political violence last week, for provoking ""a bloody massacre.""
Morales says thugs used machine guns against his supporters in an ambush on Thursday, prompting him to declare martial law in Pando. But Fernandez remains defiant, saying the deaths came not in an ambush but an armed clash, that Morales is persecuting him politically and that he will stay put in Pando's capital of Cobija. ""I won't flee,"" he said.
Bolivia's interior minister, Alfredo Rada, said Monday night that 15 people were confirmed killed in Pando. A day earlier, he had put the death toll at 30. Rada said, however, that 106 people remained missing from Thursday's violent clash.
Many of the anti-Morales blockades were dismantled over the weekend as a goodwill gesture as both sides sought to establish ground rules for negotiations. And while Bolivia was generally quiet on Monday, more than a thousand government supporters marched on the U.S. Embassy in the capital of La Paz, burning an American flag and effigies of opposition governors.
On Sunday, the U.S. Embassy issued a statement encouraging American citizens to leave Bolivia ""if the situation permits,"" and said it authorized the departure of all non-emergency embassy personnel and of family members.
Morales has expelled Washington's ambassador, accusing him of encouraging the unrest. Venezuelan President Hugo Chavez expelled his country's U.S. ambassador last week in solidarity with Morales, and the U.S. responded in kind.