Michelle Obama joins worldwide protest over missing Nigerian schoolgirls

First Lady tweets message of support for girls kidnapped by Boko Haram 

Michelle Obama has added her voice to worldwide calls for the safe return of nearly 300 kidnapped Nigerian schoolgirls.

The First Lady said on Twitter that: “our prayers are with the missing Nigerian girls and their families," adding: "it's time to bring back our girls."

Mrs Obama packaged her tweet with a photo of herself in the White House holding a white piece of paper with the message “#Bring Back Our Girls" written in black, capital letters.

The tweet was signed "-mo," indicating that she sent it herself.

The US is sending technical experts to Nigeria to help authorities find the girls.