By Gabriel Stargardter and Gustavo Palencia
TEGUCIGALPA (Reuters) - Leftist Honduran presidential candidate Xiomara Castro refused on Monday to accept partial official results that show her conservative rival on course to win Sunday's election, and a group of her supporters took to the streets.
Castro, the wife of deposed leader Manuel Zelaya, and her team said early Monday that an exit poll drawn up for her party showed she was winning. They claimed fraud and accused the electoral authority of manipulating the result.
A partial count issued by the electoral authority gives National Party candidate Juan Hernandez some 34.19 percent support, while Xiomara Castro had 28.83 percent, the body said in an update on Monday.
The preliminary tally was based on a count from 58 percent of polling booths. An election official said vote count data from far-flung precincts were still arriving at the capital.
"We are going to defend our triumph at the ballot box and if necessary will take to the streets," Zelaya said. "Until proven otherwise, we hold triumph in our hands."
"We will seek a recount ballot box by ballot box, booth by booth, town by town," Zelaya added. "We are struggling against an oligarchy in the government of Honduras."
A group of about 500 supporters began the short journey from his camp to the Marriott Hotel, where the election tribunal is set to give its next vote count announcement on Monday afternoon.
The Marriott sits right by the presidential palace, and police officers, some in riot gear, blocked off the road before the hotel, setting the stage for a showdown. Neither Castro nor Zelaya were part of the march.
"The tribunal belongs to the National Party," said Santos Aguilar, a 53-year-old salesman and Castro supporter. "We're going to take the streets to defend our rights."
Minutes before Zelaya made his comments, Hernandez said he would announce his transition team later in the day and was open to a rapprochement with Castro, but was not willing to debate the result.
"The triumph won't be negotiated with anybody," he told reporters. "The result is the one the Honduran people decided at the ballot box."
Zelaya was ousted in a 2009 coup after his opponents accused him of trying to seek re-election, which is banned under the constitution. The debacle plunged Honduras into a deep political crisis and widened tensions between the left and the right in Latin America.
The deposed leader had hoped to stage a comeback behind his wife if she reached presidential office.
Honduras was a key ally of the United States during Central American civil wars in Nicaragua, El Salvador and Guatemala, and is the region's No.1 coffee exporter.
"The result is being manipulated by the electoral tribunal to portray a reality we don't accept," Enrique Reina, Castro's running mate, told Reuters late on Sunday.
However, the U.S. ambassador to Honduras and the head of the European Union's election observers said the voting process was clean and urged the participants to respect the results.
Hernandez said Mauricio Villeda, the Liberal Party candidate lying a distant third who also initially challenged the partial count, had called to congratulate him.
Castro was first to claim victory on Sunday, citing an exit poll drawn up for her own party and telling cheering supporters: "I am the president."
Then the electoral authority published preliminary official results showing she was trailing Hernandez - indicating the possible continuity of outgoing President Porfirio Lobo's right-leaning economic policies.
Hernandez posted a photograph on Twitter late on Sunday of himself and supporters praying on their knees. "Thanks to my God, and thanks to the people of Honduras for this triumph," he wrote.
He has vowed a tough militarized response to drug gang violence that has earned Honduras the dubious distinction of having the world's highest murder rate, or more than 85 killings per 100,000 people.
(Additional reporting by Miguel Gutierrez; Writing by Simon Gardner; Editing by Philip Barbara)