A mortar attack that killed 15 students at Damascus University marks a rebel escalation in the Syrian capital ordered by foreign governments, Information Minister Omran al-Zohbi said on Friday. "The terrorists' mortar attacks on residential areas, schools, universities and hospitals is the result of foreign orders to stage a full-scale escalation," Zohbi told state news agency SANA. The aim is to "give the impression that terrorists are attacking the heart of the capital... and that they are achieving the goals of their aggression against Syria," he said. Zohbi said that the "foreign order" to carry out Thursday's attack on the architecture faculty close to Umayyad Square in the city centre "comes in tandem with the decision to hand Syria's seat in the Arab League" to the opposition. "Turkey, Qatar and several Arab and Western spying agencies are trying their best... in a last-ditch attempt to overthrow (the regime) and bring about the collapse of the Syrian state," he said. On Monday, opposition chief Ahmad Moaz al-Khatib addressed the Arab League's annual summit in Qatar after the bloc decided to give his National Coalition the Syrian seat vacant since it suspended Damascus in November 2011. Arab leaders also affirmed the "right of every state to offer all forms of self-defence, including military, to support the resistance of the Syrian people and the (rebel) Free Syrian Army." Summit host Qatar and its heavyweight neighbour Saudi Arabia have long championed arming the rebels. Western governments have so far limited themselves to non-lethal aid but Britain and France have called on fellow EU members to agree to an easing of the bloc's arms embargo to allow deliveries to the rebels. There are almost daily clashes on the outskirts of Damascus but, despite talk of a "final battle" for the capital, insurgents have so far been unable to launch a major offensive.