Syrian opposition fighters said they had captured a major Syrian army base in the south of the country on Tuesday, a defeat that would add to the pressure on President Bashar al-Assad after other recent setbacks."We announce the liberation of Liwa 52," said Issam al-Rayyes, spokesman for the "Southern Front" alliance of opposition groups. The base "Liwa 52", or the 52nd Brigade, is near the city of Deraa near the border with Jordan.Bashar al-Zoubi, leader of one of the Southern Front groups, also said the attack launched on Tuesday morning had resulted in the capture of the base.Syrian officials could not immediately be reached for comment.