about the saudi air campaign which is caused hundreds of civilian casualties. now the united nations is worried about a humanitarian crisis and calling for a cease-fire from all sides. let's get the latest from nima elbagir in yemen. >> reporter: al qaeda are clearly moving into the security vacuum. they have taken the third largest airport in yemen. they have as you said, an oil platform now. they moved in to repel the houthis advances. they seem to be putting up their black flags in a number of areas that they don't have complete control of. they seem to be trying to honeycomb that territory that has as yet not fought over fully will the houthi and president hadi in yemen.