On the first anniversary of the abduction of more than 200 Nigerian schoolgirls this week, Nobel Peace Prize winner Malala Yousafzai wrote an open letter to the girls who are still held captive.

Malala Yousafzai has written a heartfelt letter to her 219 “brave sisters” abducted by the Islamist militant group, Boko Haram, on April 14 last year.

Related content: One year since their abduction, the world has marked the disappearance of these Nigerian schoolgirls.

Malala Yousafzai.

In the letter, the Nobel Peace Prize winner promises not to rest until the girls are reunited with their families.

“My name is Malala. I am a Pakistani girl your age,” the 17-year-old writes.

“I am one of the millions of people around the world who keep you and your families foremost in our thoughts and prayers. We cannot imagine the full extent of the horrors you have endured. But please know this: We will never forget you.”

Read this: What really happened to the 219 missing Nigerian schoolgirls.

Yousafzai encourages others to “tell the girls and their families that the world has not forgotten them” by signing her open letter.

Video claiming to show the kidnapped Nigerian schoolgirls.

Here is the full letter:

Will you put your support behind Malala and #bringbackourgirls?