Thousands of civilians, including many children, will die unless a Saudi-led coalition fully lifts a blockade that has "chocked off" aid supplies to Yemen, the heads of three UN agencies said Thursday. 

"Together, we issue another urgent appeal for the coalition to permit entry of lifesaving supplies to Yemen in response to what is now the worst humanitarian crisis in the world... Without them, untold thousands of innocent victims, among them many children, will die", said a joint statement.