MANAGUA (Reuters) - Nicaragua’s Congress approved a sweeping amnesty law during a Saturday session that will offer protection to police and others who took part in a violent clampdown on anti-government protesters over the past year.

FILE PHOTO: Riot police are pictured during a protest against the government of Nicaragua's President Daniel Ortega in Managua, Nicaragua March 16, 2019. REUTERS/Oswaldo Rivas/File Photo

Passed by lawmakers allied with President Daniel Ortega who control the chamber just a day after it was introduced, the legislation faced blistering critiques from domestic opposition and provoked a stern rebuke from the United Nations’ top human rights official.

The law was approved by 70 votes from Ortega’s Sandinista National Liberation Front (FSLN) in the 92-member chamber. It also allows for the release of detainees arrested during anti-Ortega protests, individuals who the former Marxist guerilla has dubbed terrorists.

Lawmakers who backed the law said they were taking a stand for national unity.

“We are witnessing an act of sovereignty that seeks peace and reconciliation,” lawmaker Edwin Castro, who leads the FSLN caucus in the Congress, said during debate on the proposal. “It hurts to have to give amnesty to confessed murderers of police officers and to torturers,” he added.

The government and its allies have often blamed the opposition for the violence, while a commission from the Organization of American States concluded that crimes were perpetuated by police and FSLN supporters.

Demonstrations erupted in April 2018 when Ortega tried to cut welfare benefits, and gradually spread into a broader protest movement against the president’s rule.

More than 700 people were arrested in demonstrations and 325 mostly opposition protesters died in clashes with security forces, while over 60,000 Nicaraguans have gone into exile due to political strife over the last 14 months, rights groups say.

The new amnesty law extends protections to “people who have not been investigated, who find themselves under investigation” or in criminal processes and “complying with their sentences,” according to the text.

Critics of the law blasted it as serving the interest of Ortega and First Lady Rosario Murillo, who also serves as vice president.

“The amnesty is a promise of impunity for those who committed crimes under the orders of Ortega and Rosario Murillo,” said Maria Teresa Blandon, a member of the opposition Blue and White National Unity movement.

U.N. human rights chief Michelle Bachelet said in a statement on Friday that the law “could impede the processing of potentially responsible persons for grave violations of human rights” committed during the protests.

Ortega has pledged to release those detained in the anti-government protests as a gesture of good faith to the opposition and a bid at national dialogue.

Nearly 200 detainees who the opposition describes as political prisoners remain behind bars while another 520 have been freed, according to a rights group that supports those arrested during the protests.