The United Nations has joined the chorus of international outrage at the kidnapping of over 250 girls in Nigeria.

The Security Council said it is considering “appropriate action” against those responsible.

Islamist group Boko Haram abducted the girls from a school in Chibok in northeastern Nigeria on April 14, while eight more girls were taken from another village earlier this week.

Global demonstrations calling for action to locate the girls and accusations from Amnesty International that the Nigerian army had advanced warning of the raid on the school are increasing pressure on Nigerian President Goodluck Jonathan: “As a father and the president of this country, I feel pained, I don’t sleep with my two eyes closed and I will not sleep with my two eyes closed until these girls are brought safely back to their parents,” he said.

US First Lady Michelle Obama is to deliver her husband’s weekly radio address to condemn the kidnapping.

Michelle Obama has become a high profile vocal campaigner for the release of the girls.

International search and rescue personal have begun to arrive in the country as the hunt for the girls gathers momentum.