Violence broke out between government and opposition supporters who both claimed victory in Nicaragua's capital in local elections, leaving several wounded, and one dead according to the opposition.
Supporters of Sandinista candidate Alexis Arguello were seen attacking some 3,000 opposition supporters with sticks and stones as they marched toward a counting center. Three people were shot and wounded in the ensuing violence, an AFP correspondent said.
Nicaraguan police said four people were wounded by bullets but no one had died, after opposition leader Arnoldo Aleman said one person had been killed.
"I've been told that one of those shot has died," Aleman said.
Early official returns showed Nicaragua's ruling Sandinista National Liberation Front ahead in around 100 of 146 municipalities, including the capital, after Monday's elections, which were marked by violence and allegations of fraud.
But the opposition claimed to have won in 58 municipalities, including Managua, and denounced irregularities, as protesters took to the streets.
The government of President Daniel Ortega, a former Marxist guerrilla, came under fire even before the polls for barring two opposition parties from fielding mayoral candidates and for police raids against non-governmental organisations.
Ortega led Nicaragua from 1979 to 1990 after Saninista guerillas overthrew the Anastasio Somoza dictatorship. He was re-elected president in 2006. The United States has been vocal in its opposition to Ortega, whom they see as bolstering an anti-US bloc in Latin America.
The US State Department on Monday urged the Central American country to ensure that results reflect the will of the people.