Two groups have claimed responsibility for the attack - a spokesman for the Free Syrian Army described it as the start of the "volcano" they had promised. And, indeed, the loss of a key minister comes as rebel forces continue their all out offensive against the government - and as world leaders prepare for UN Security Council talks on the crisis later this week. In a moment, we'll be speaking to our Middle East analyst Michael Lüders about the growing crisis in Syria - but first, we have this report.