Bombing kills head of Syrian rebel group, activists say

DAMASCUS, Syria -- The head of one of Syria's largest rebel groups was killed in a suicide bombing alongside many of his leading fighters, activists and state media reported Tuesday night, an attack likely to further weaken the country's already shaky armed opposition.

Hassan Aboud of Ahrar al-Sham, an ultraconservative Syrian rebel group, was killed in the northwestern town of Ram Hamdan in the Syrian province of Idlib, an activist collective called the Edlib News Network and the Britain-based Syrian Observatory for Human Rights reported.

Both groups said that other leading group members were killed after a suicide bomber detonated his explosives belt in a meeting of Ahrar al-Sham's leaders. The Observatory bases its information from a network of activists on the ground.

The Edlib News Network said that over 40 people were killed, including four other leaders of Ahrar al-Sham. The Observatory said "tens" people were killed but did not provide a specific number. Differing casualty figures are routine immediately after attacks in Syria.

The group previously fought against the extremist Islamic State of Iraq and Syria group, which now holds a swath of territory across Syria and Iraq. Ahrar al-Sham had blamed ISIS for the killing of one of their leaders in February, a man known as Abu Khaled al-Souri.

Ahrar al-Sham advocates the implementation of an ultraconservative interpretation of Islam, but had worked with more moderate rebel groups trying to oust President Bashar Assad.

It had become the most prominent member of a broader rebel coalition known as the Islamic Front. But that group was struggling in recent months after it appeared that donor funding had dried up.

CBS News correspondent Clarissa Ward says if Hassan Aboud has indeed been killed, it would be a huge blow for the Islamic Front, which is essentially the only Islamist counterweight to ISIS and Nusra. Insiders have told Ward the Islamic Front is close to crumbling.

If they fall, Ward reports, that will basically only leave the FSA (or so-called moderates) and ISIS and Nusra. So the question is which side will the Islamic Front supporters gravitate towards.