A Nobel peace laureate has urged a global effort to secure the release of over 200 Nigerian schoolgirls abducted by Boko Haram Takfiri militant group.

“As we mark this tragic 300th day of captivity for hundreds of kidnapped Nigerian schoolgirls, I call on people everywhere to join me in demanding urgent action to free these heroic girls … Nigerian leaders and the international community can and must do much more to resolve this crisis and change their weak response to date,” said Malala Yousafzai in the Nigerian city of Lagos on Sunday.

“If these girls were the children of politically or financially powerful parents, much more would be done to free them. But they come from an impoverished area of northeast Nigeria and sadly little has changed since they were kidnapped.” added Yousafzai, the Pakistani activist who won the 2014 Nobel Peace Prize for her campaign against the suppression of children.

Back in April 2014, Boko Haram militants kidnapped 276 students from their secondary school in the northeastern Nigerian town of Chibok. Reports say 57 of the girls managed to escape but 219 are still missing.

The abduction case has drawn national and international condemnation. The Nigerian administration has been heavily criticized for failing to secure the release of the kidnapped girls.

Boko Haram, whose name means “Western education is forbidden,” says its goal is to overthrow the Nigerian government.

It has claimed responsibility for a number of deadly shooting attacks and bombings in various parts of Nigeria since the beginning of its operations in 2009, which have left over 13,000 people dead and 1.5 million displaced.

Boko Haram has also conducted military operations in Nigeria’s neighboring countries, Cameroon, Chad, and Niger.