Nicaraguan police said Saturday they had arrested and later released 107 people trying to take part in a demonstration calling for the release of hundreds of political prisoners.

The demonstrators were responding to a call by the opposition Blue and White National Unity (UNAB) for a march through the center of Managua.

However, before they could gather for the march, they were reportedly attacked and captured by the police, who outlawed the protest for not respecting the Constitution of Nicaragua.

The police released a statement claiming it fulfilled its constitutional duty of guaranteeing the safety and rights of citizens by apprehending 107 people for disturbing public order.

The police version of the incident was denied by witnesses, local human rights organizations, the Inter-American Commission on Human Rights (IACHR), the United States embassy in Nicaragua, opposition groups and reporters covering the events, as well as by photos and videos posted on social networks by Nicaraguans.

In the vicinity of a banking complex, officers of the Directorate of Special Operations - an elite body of the police force - beat a photojournalist and confiscated his equipment. They also arrested a woman who was next to reporters.

Several videos showed the police breaking into a private commercial center next to a hotel and attacking people inside.

Among the people arrested were former education minister Humberto Belli, former Sandinista guerrillas Monica Baltodano and Moises Hassan, members of the group negotiating with the government - Azahalea Solis and Max Jerez, opposition leader Ana Margarita Vigil, activist Sandra Ramos, veteran journalist Marlen Chow and a minor, according to UNAB.

The incident comes during a moment of crisis in the country, which in the last 11 months has left 325 people dead, according to IACH, although several local human rights groups have counted 561 dead. The government headed by President Daniel Ortega only recognizes 199 deaths and says it is the target of a coup attempt by right-wing opponents.

The Nicaraguan government has been holding negotiations with the opposition Civic Alliance for Justice and Democracy, which has said that the government delegation avoids discussing key issues.

At least 762 people remain in some form of detention after taking part in anti-government protests, according to Pro-Liberation Committee of Political Prisoners of Nicaragua.

The IACHR has accused Ortega's government of committing crimes against humanity, while the application of the Inter-American Democratic Charter of the Organization of American States is underway and could result in Nicaragua's suspension from the OAS.