A US citizen and two Nicaraguans died Saturday amid the violence of the sociopolitical crisis suffered by Nicaragua.

The unrest also left two wounded and police detained dozens of people, who were released hours later.

The Nicaraguan Police reported the death of the American Sixto Henry Vera, 48, and attributed that homicide to "criminal groups...with firearms, mortars and Molotov cocktails, (who) operate in the sector" of the Polytechnic University of Nicaragua (Upoli), in Managua, which is held by a group of students protesting against the government.

Vera, born in New York of Ecuadorian parents, was found dead in a street in Managua beside two burned vehicles.

The American, who owned a bar and restaurant in Managua and was celebrating his birthday, received a call in which he had apparently been told that a friend had been injured in the area where he was found dead.

Immediately he went out to help the friend and was eventually ambushed, shot and his truck burned, according to the version his staff told the Nicaraguan Association for Human Rights (ANPDH).

The American ambassador in Managua, Laura Dogu, said on Twitter that the death of one of her fellow citizens "is of great concern" for Washington, which expressed its condolences to the victim's family.

Marcos Pomares Varela was found next to the American with "very serious injuries", according to the police report.

Police also reported the death of Darwin Alexander Salcedo Vílchez, 19, who died in a hospital in the municipality of Estelí, 149 kilometers north of Managua, where he was admitted with a bullet in his head.

That institution affirmed that Salcedo Vílchez was a "victim of criminal groups" in Estelí.

Meanwhile, the opposition Student Movement April 19 reported that a group of civilians who maintain a barricade in Masaya, 28 kilometers southeast of Managua, were attacked by agents of the National Police and groups related to the government, leaving one dead and 22 detained.

That victim, who does not appear in the police report, was identified as Donald Ariel López, according to the executive secretary of the ANPDH, Álvaro Leiva.

The police acknowledged that they detained eleven people in the city of Masaya who were wearing hoods, carrying firearms and mortars, and who "carried out terrorist acts against the National Police" in that town.

"Police forces repelled this terrorist and criminal act, capturing 11 criminals," he said.

The police also reported damage to the headquarters of the municipal government of Diria and the municipal house of Sandinismo, as well as to a restaurant, a store, a hotel, eight houses, and in a complex that houses offices of state institutions.

Also two vehicles, a truck, a van and a motorcycle were burned.

Likewise, he indicated that in different municipalities of Nicaragua there are 'barricades' or roadblocks, where, they claim, "they continue to charge tolls, damage road infrastructure, private and state vehicles, violating the constitutional right to free movement in the national territory."

Saturday marks 46 days of Nicaragua's sociopolitical crisis, the bloodiest since the 1980s, which has left at least 108 people dead and about 1,000 wounded, according to the Nicaraguan Center for Human Rights (Cenidh).

The protests against the government of Daniel Ortega began in April for failed social security reforms, and became more intense as a result of killings during the demonstrations.