One of Rwanda’s most prominent opposition leaders has walked free after the government approved the early release of more than 2,100 prisoners with little explanation.

Supporters of Victoire Ingabire and the state-run The New Times newspaper posted photos of the opposition leader leaving Nyarugenge prison hours after the justice ministry’s announcement.

Ms Ingabire’s release surprised many in the capital, Kigali, because it is unusual for long-time President Paul Kagame to pardon potential challengers.

Also approved for early release was musician Kizito Mihigo, convicted on charges of conspiring against the government, who along with MS Ingabire received a presidential commutation.

The ministry statement said both had made their most recent requests for clemency in June.

Ms Ingabire, head of the FDU-Inkingi opposition party, was arrested in 2010 and found guilty of conspiracy to undermine the government and denying Rwanda’s 1994 genocide, charges that she denied. She was sentenced to 15 years.

Human Rights Watch called the charges politically motivated and linked to her criticism of the government ahead of the 2010 presidential election.

Rwanda’s government has long been accused by rights groups of suppressing the opposition and having a justice system that lacks independence, which the government has denied.

Human Rights Watch has expressed concern that the government uses accusations of “genocide ideology” as a way to silence critics.

Some 800,000 people, mostly ethnic Tutsis, were killed by Hutu extremists during the Rwandan genocide, according to the United Nations.

Some in Rwanda objected to Ms Ingabire’s release. “Anyone who peddles … ethnic politics must be told in no uncertain terms that it won’t be tolerated. Her release doesn’t do that,” Christopher Kayumba, a lecturer at the school of journalism at the National University of Rwanda, said in a Twitter post.

Still detained in Rwanda is Diane Rwigara, who tried to challenge Mr Kagame in last year’s election but was disqualified from running over allegations that she forged some of the signatures on her nomination papers. She denied it.

Ms Rwigara later was charged with inciting insurrection against the state.