Sanaa (AFP) - UN Secretary General Ban Ki-moon called for international action to end the Saudi-led air campaign on Huthi rebels as intense bombing hit Yemen again Friday and Al-Qaeda seized more ground in the chaos.Columns of smoke rose over an arms depot targeted by warplanes east of the capital Sanaa, witnesses said.The facility belonged to the elite Republican Guard, which remains loyal to former president Ali Abdullah Saleh.Renegade troops loyal to Saleh are allied with the Huthi rebels, whose sweeping advance forced President Abedrabbo Mansour Hadi to flee to Riyadh last month.Following heavy overnight air strikes in the north, coalition aircraft also hit the presidential palace in the southern city of Taez, the witnesses said.Coalition spokesman Brigadier General Ahmed al-Assiri said that "from this afternoon we have started operations in Taez".Speaking in Riyadh, he added that there had been 100 sorties in Yemen on Thursday, indicating there is no end in sight to the operation."This works needs patience, persistence and precision.