There have been violent clashes in Nicaragua between supporters and opponents of President Daniel Ortega, following his disputed reelection on Sunday.
At least four people were shot dead in the north of the country, police said.
The main opposition candidate - Fabio Gadea - has denounced the election result as fraud.
Official results gave Mr Ortega of the governing Sandinista party almost 63% of the vote.
Mr Gadea of the Liberal Independent Party came second with 31%.
European Union election observers have questioned the transparency of the vote and the independence of the electoral authorities.
"There is no doubt Mr Ortega and the Sandinistas won the elections," the head of the EU mission Luis Yanez-Barnuevo said.
"But I am not saying that they won cleanly and transparently, because we don't know what would have happened without all these tricks and ruses," he added.
The worst of the post-election violence happened in two northern towns.
Three opposition supporters were shot dead in the town of San Jose de Cusmapa near the border with Honduras, and a Sandinista activist was killed in Siuna on the Atlantic coast.
There were also clashes between government and opposition supporters in the capital, Managua.
Nicaraguan police say 46 officers have been injured, including six with bullet wounds, trying to contain post-election violence across the country.
President Ortega, 65, has urged his opponents to accept the result.
He was able to stand for reelection only after the Sandinista-controlled Supreme Court overturned a ban on serving consecutive terms in the top office.
He previously ruled Nicaragua for 11 years after leading the Sandinista revolution that overthrew dictator Anastasio Somoza in 1979.
He returned to power in elections in 2006 after three failed attempts.