Israeli airstrikes hit Yemen’s main airport as a civilian Airbus 320 with hundreds of passengers on board was landing and a U.N. delegation was waiting to leave, the U.N.’s top humanitarian official in Yemen said Friday.

Israeli forces unleashed a series of deadly strikes on the Yemeni capital Sanaa and the western city of Hodeidah on Thursday, according to Houthi-run media, killing at least four people and injuring more than a dozen others.