Managua: Nicaraguan President and one-time Sandinista revolutionary Daniel Ortega was re-elected in a landslide, according to results released on Monday, overcoming a constitutional limit on re-election and reports of voting problems.

Ortega had 63 per cent support compared to 31 per cent for his nearest challenger, Fabio Gadea, with 86 per cent of the votes counted from Sunday's election. Former president Arnoldo Aleman was a distant third with six per cent.

The size of Ortega's margin of victory is likely to reduce the impact of reports of irregularities during voting.

A domestic group of observers, Let's Have Democracy, said it recorded 600 complaints of voting irregularities, a handful of injuries in protests and 30 arrests.

Gadea, election observers and oppositions groups raised questions about the validity of the vote, as did the United States.

State Department spokeswoman Victoria Nuland repeated US concerns over whether the elections were transparent and free of intimidation, violence and harassment.

"There are quite a number of reports, and we're concerned because the conditions weren't good going in," Nuland said. "And frankly, if the Nicaraguan government had nothing to hide, it should have allowed a broad complement of international monitors."

Strict guidelines

The Ortega government issued strict guidelines for election observers. International teams had to negotiate for more access, and Nicaraguan observers didn't even bother to get credentials.

A team from the European Union said it would issue a report yesterday after complaints that included a polling place set on fire, election officials obstructing voters from opposing parties and protests by those who didn't receive their voting credentials.

The head of the Organisation of American States observer mission, Dante Caputo, initially complained that its observers were being denied access to 10 polling stations, but later said in a statement that the issue was resolved.

Maturity

OAS General Secretary Jose Miguel Insulza said he talked to Ortega on Sunday, saying despite the anticipation of tensions and violence, the election showed "the maturity of the Nicaraguan people and their dedication to peace".

Eliseo Nuñez, who headed Gadea's campaign, said 20 per cent of his party's representatives had been blocked from overseeing polling places "by paramilitary mobs".

"We can't accept the results because they don't reflect the will of the people, rather the will of the election council," Gadea said.