The government of Bolivia has resumed talks with opposition leaders after a deep political crisis triggered violent unrest which resulted in a declaration of martial law.

Government officials said Sunday at least 28 people were killed in last week's fighting between government and opposition supporters.

Interior Minister Alfredo Rada announced the near doubling of the death toll after more bodies were found following Thursday's clash in the northern province of Pando.

South American leaders are to gather later Monday in Chile at an emergency summit to try to find a resolution to the situation.

The crisis began when supporters of right-wing opposition governors fired shots at pro-government peasant farmers.  The clash happened during a protest over proposed constitutional reforms by Bolivian President Evo Morales.

Mr. Morales has accused Pando's governor, Leopoldo Fernandez, of ordering a massacre.  Fernandez denies having anything to do with the violence.

The violence prompted Mr. Morales to declare martial law in Pando and send troops to take control of the airport in the provincial capital, Cobija.

Mr. Morales last week ordered U.S. Ambassador Philip Goldberg to leave the country, accusing the diplomat of instigating protests.

In La Paz Sunday, Goldberg told reporters the accusation is false and unjustified.

Some information for this report was provided by AFP, AP and Reuters.