Al-Qaida divisions may aid Assad as he eyes Syria's Idlib

A recent wave of detentions and a spate of violence within al-Qaida have also raised fears of an all-out war between insurgents in the heavily populated province near Turkey as Assad's forces make their push.

Assad lost control of Idlib nearly three years ago and he has vowed to recapture it, but that is expected to be a bloody and costly fight. The militant haven is heavily fortified and home to thousands of fighters who transferred there from other parts of the country. It is also where tens of thousands of civilians settled after fleeing fighting in Aleppo, Homs, the suburbs of Damascus and elsewhere.

Tensions inside Idlib have been on the rise for months, reflecting a power struggle between hard-line foreign fighters loyal to al-Qaida's leader, Ayman al-Zawahri, and its more moderate Syrian members.

The tensions worsened in late November after a wave of detentions by an al-Qaida-linked group against more extremist, mostly non-Syrian members. Among those detained were two of al-Qaida's most esteemed leaders and founding members of the extremist group's branch in Syria, who were set free days later after pressure by factions within the group who threatened to withdraw from the battlefield in protest.

The Nov. 27 raids by the al-Qaida-linked Hay'at Tahrir al Sham — Arabic for Levant Liberation Committee, also known as HTS — took many by surprise and angered al-Zawahri, who accused his top man in Syria of betrayal.

The detentions, ordered by HTS leader Abu Mohammed al-Golani, were the clearest indication yet of the sharp divisions within the international terror network. They also come as al-Golani appears to be edging closer to Turkey, which is trying, along with Iran and Russia, to bring an end to the country's civil war, now in its seventh year.

HTS was until recently on the ascendant in Syria, crushing potential opponents in Idlib as its rival, the Islamic State group, faced significant setbacks, losing most of the territory it once held in the country.

Those who were detained included Jordanian citizens Sami Oraidi, al-Qaida's former top religious figure in Syria, and the highly secretive former military commander in southern Syria, Ayad Toubasi, also known as Abu Julaybib al-Urduni, brother-in-law of the late al-Qaida in Iraq leader, Abu Musab al-Zarqawi.

After their detentions, other al-Qaida officials, including a prominent cleric, went to ask al-Golani why their comrades were detained. But the men ended up being taken into custody themselves.

Days after al-Shami's warning, intense clashes broke out between HTS and the Jund al-Malahem faction that split from it in October and is close to the detained al-Qaida officials, leaving at least seven people dead.