Yemen is seeing its most violent clashes yet, a day after President Ali Abdullah Saleh refused to sign a brokered deal to step down from his position of power with immunity. Though previous clashes have resulted in more deaths, government officials and rebels were both heavily armed Monday, raising the dangerous prospect of a full-blown war. Both sides opened fire on streets near the Ministry of Industry and Trade and the Saba News building in attempt to take over the strategic landmarks. The headquarters of Yemen's national airline was also a fighting point and eventually went up in flames. Secretary of State Hillary Clinton said the U.S. is "deeply disappointed" over Saleh's broken promise and "outraged" that Saleh's armed supporters cornered diplomats who were waiting for him to sign over power.