An air strike has hit a hospital run by Medecins sans Frontieres in northern Yemen, killing at least 11 people And another 19 people were injured in the attack in abs, in Hajjah province. Local people said the hit follows days of air raids in the area. The first rescue workers to arrive at the scene had to move cautiously, fearing that the circling planes might attack again. The blast immediately killed nine people, including an MSF staff member. Two more patients died while they were being transferred to another hospital. The conflict in Yemen that began in 2015 has left more than 6,400 people dead, half of them civilians, and displaced 2.5 million others. MSF said more than 4,600 patients had been treated at the abs hospital since MSF began supporting it in July 2015. A spokesman for the United Nations said the Organisation was aware of the latest reports from Yemen and was trying to gather some details.