Fernando Lugo addresses supporters at the Presidential Palace in Asuncion June 22, 2012. [Photo/Agencies]

BUENOS AIRES - The Paraguayan Senate voted on Friday to impeach President Fernando Lugo in what several South American neighbors perceived to be a thinly-veiled attempt by political opponents to seize control of the government.

The speedy impeachment trial, which ended with 39 votes in favor and four against, with two abstentions, opened the way for Vice President Federico Franco to immediately take his place while sparking violence in the capital Asuncion between Lugo's supporters and security forces stationed around the National Parliament building, where the trial took place.

The Senate called on Franco to "take the corresponding oath of office in 30 minutes" to complete the presidential term, which concludes in August 2013.

Outside the Parliament building, riot police and National Guard troops, some on horseback, used tear gas and water cannons to disperse some 5,000 who had gathered in support of Lugo in the capital's Democracy Square.

Minutes later, Lugo accepted the ruling during a televised speech to the nation, saying he respected the legal procedure " even though the law has been twisted" by political interests.

Paraguay's conservative opposition-controlled Congress called for the impeachment of the left-leaning president Thursday, accusing him of "poorly discharging his duties" after a deadly land dispute between squatters and police ended in fatalities on both sides.

Opponents say Lugo, a former Roman Catholic priest who entered politics to help champion the poor, failed to deliver on his main campaign promise of land reform, even though congressional opposition has been the main obstacle to proposed reforms.

Claiming that the trial was politically motivated, Lugo had described the impeachment proceedings as a "parliamentary coup," a sentiment echoed by the governments of Venezuela, Bolivia and Ecuador.

"More than a coup d'etat against a president, as they used to do years ago, it is a parliamentary coup with accusations that do not conform to the truth," he had told a local radio station in Asuncion.

Before the impeachment ruling, Ecuadorean President Rafael Correa warned Friday that if Paraguay's opposition forces manage to "illegitimately" remove Lugo from office, the Union of South American Nations (UNASUR) could refuse to recognize the new government or even close their borders to Paraguay.

UNASUR's founding charter states that member countries can call for sanctions or other measures to re-establish order in another member country should its democratic system come under threat.

UNASUR member nations include Peru, Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Surinam, Uruguay and Venezuela.

Though Lugo and his vice president had joined forces to create their coalition government, Franco's party had broken with the president.