Yemen's President Abd-Rabbu Mansour Hadi left his refuge in Aden for Saudi Arabia on Thursday as Houthi rebels battled with his forces on the outskirts of the southern port city. Throughout the day, warplanes from Saudi Arabia and Arab allies struck at the Shi'ite Houthis and allied army units, who have taken over much of the country and seek to oust Hadi. Warplanes resumed bombing the Houthi-held capital Sanaa on Thursday evening, shaking whole neighborhoods and terrifying residents. Several civilians have been reported killed in Sanaa. "My whole family and I are preparing to sleep in the basement, as it's the safest part of the house," said resident Fawzia Nedras. "The windows are rattling and we think they may break. We live near the airport, where we think a lot of the Houthi leaders are living and many of the air strikes are." Houthi leader Abdel-Malek al-Houthi said in a televised speech Yemenis would confront the "criminal, unjust and unjustified aggression" by Saudi Arabia. Residents and security officials said the second night of air strikes throughout Yemen targeted air and ground force bases loyal to ex-president Ali Abdullah Saleh, whose forces have bolstered the Houthi advance. The Saudi-led military intervention marked a major escalation of the Yemen crisis, in which Iran supports the Shi'ite Muslim Houthis, and Sunni Muslim monarchies in the Gulf back Hadi and his fellow Sunnis in Yemen's south.