Nigeria's new President marked the first anniversary since more than 200 schoolgirls were abducted by Boko Haram militants by saying he did not know if they would ever be found. Muhammadu Buhari, who won the presidential election two weeks ago, said his administration would do everything in their power to bring the students home - but said he could not promise they would find them. The announcement came as a march was held through the Nigerian capital of Abuja to mark the first anniversary since the girls were abducted from a secondary school in Chibok. Protestors marched through Abuja with red tape over their mouths, carrying a poster with pictures of some of the missing girls. It is now a year since more than 200 schoolgirls were kidnapped by Boko Haram militants . Muhammadu Buhari said his government will do 'everything in their power' to find and return around 220 missing schoolgirls to their families, as young girl joins the rally outside the Nigerian ministry of education . Almost 300 girls were taken away in trucks on the night of April 14 to 15 2014, after the terrorists from Boko Haram - meaning 'Western education is sinful' - broke into their school by pretending to be guards. The students were forced to convert to Islam and marry group members. The attack sparked worldwide condemnation and a huge campaign called '#bringbackourgirls' - but more than 200 are still missing after others were freed or killed. In a statement, former military rule Buhari said he would take a different approach to the crisis as outgoing President Goodluck Jonathan, who was criticised for responding slowly to the kidnapping after arguing a hasty rescue would risk killing them. A rally was also held in New York, attended by congresswoman Carolyn Maloney (right), one year since the schoolgirls were kidnapped. Nigeria's new president said the whereabouts of the students is not known . 'We do not know if the Chibok girls can be rescued', Buhari said. 'Their whereabouts remain unknown. As much as I wish to, I cannot promise that we can find them.' 'My government will do everything in its power to bring them home', he added. As families mark one year since their daughters were abducted, Lawan Abana - whose two nieces were among those kidnapped - said he is still hopeful they will be found. 'It was handled in a lousy manner', he said. 'We are confident that the girls are still alive.' Amnesty International said in a report on Tuesday that Boko Haram has kidnapped at least 2,000 Nigerian women and girls since the start of 2014, many of whom were sexually abused or trained to fight. Pictured in May last year, the missing Nigerian schoolgirls were filmed wearing the full-length hijab . Boko Haram - which means 'Western education is sinful' - forced the girls to convert to Islam and marry . The document, which includes scores of victim testimonies, accuses Boko Haram of rape, forced marriages and coercing them into armed attacks, sometimes on their own villages. One 19-year-old, who asked not to be named, told Amnesty she had been repeatedly raped by gangs of up to six men. 'I was among the girls trained to shoot. I was also trained how to use bombs and how to attack a village', she said. With help from state neighbours Niger, Cameroon and especially Chad, the rebel Boko Haram force in Nigeria have been forced to retreat from an area the size of Belgium in the last few weeks.
New President says he doesn't know if 200 missing girls can be rescued .
March through Nigerian capital marks one year since the kidnapping .
More than 200 schoolgirls kidnapped last April by Islamic extremists .
Crisis sparked worldwide criticism and #bringbackourgirls campaign .