(ANSAmed) - BEIRUT - Al Qaida militants have withdrawn over the past few hours from the main Syrian eastern city of Dayr az Zor in the region bordering with Iraq's western al Anbar area at the centre of clashes between Baghdad's government forces and al Qaida-linked insurgents, activists in Dayr az Zor said via Skype on Tuesday. They said last night members of the Islamic State of Iraq and the Levant (ISIS) pulled out of the area after local rebels on Monday surrounded their headquarters in the city. The sources claimed ISIS, which has been under attack for days in the Syrian regions of Idlib, Aleppo and Raqqa, has now deployed outside Dayr az Zor.

The UK-based Syrian Observatory for Human Rights quoted local medical sources as saying that over 30 al Qaida militants died over the past few hours in the north-western region of Idlib in clashes between al Qaida fighters and local rebels. The dead militants are all reportedly non-Syrian members of ISIS.

Al Qaida militants have executed overnight 50 Syrian activists they had detained in Aleppo, activists in the northern Syrian city told ANSA on Tuesday in a Skype interview.

The prisoners were killed at a former eye hospital in Aleppo, the activists said.

The sources said the executions were carried out by members of the Islamic State of Iraq and the Levant, an al Qaida-linked militant group in Syria which has been attacked by local insurgents over the past few days.

The massacre reportedly took place in the eastern Qadi Askar district of the city.

No videos or pictures are currently available to prove that the activists detained in the al Qaida prison were murdered.

An association representing reporters in Aleppo on Tuesday morning condemned the 'shameful massacre', claiming that doctors working at field hospitals in the Aleppo area were among those killed by al Qaida.

Neither Father Paolo Dall'Oglio, a Roman Jesuit priest abducted in Syria six months ago, nor Western journalists are among the dozens of prisoners held by al Qaeda and freed by local insurgents Monday in Raqqa, the main city of northern Syria which has been at the centre of a major offensive by Islamic rebel groups against the Islamic State of Iraq and the Levant (ISIS), an al Qaeda affiliate whose mid-level and top leaders are mostly foreigners.

As part of a response against attacks carried out since last Friday by the diverse members of the Syrian insurgency in the regions of Idlib, Aleppo and Raqqa, a self-proclaimed 'emir of al Qaida' of Algerian descent with a Belgian passport announced the creation of a 'regiment' with about 100 suicide attackers ready to strike anti-regime Syrian rebel targets.

Meanwhile artillery and air force regime units hit civilian targets in areas supporting rebels, avoiding ISIS posts and barracks - highlighting once more the fact that the Syrian regime and al Qaida appear to have the common goal of fighting the fragmented insurgency front. However insurgents have gained ground in Raqqa, in clashes with ISIS, thanks to the presence of Jabhat al Nusra, an al Qaeda-linked group which is however mainly formed by Syrians who appear to have a more 'national' rather than 'regional' agenda.

Some 50 prisoners who were freed by insurgents in Raqqa are Syrian men: many claimed to be members of the Free Syrian Army arrested months or weeks ago by ISIS.

A Turkish photojournalist with daily Milliyet, Buenyamin Ayguen, also returned home after he was released by Islamic group Ahrar ash Sham and handed over to Ankara's intelligence services.

Sources close to humanitarian aid workers in Syria said high-profile detainees including Western reporters and Father Paolo Dell'Oglio had already been moved to another location and were not detained by ISIS in the Raqqa region anymore, as several other sources had reported in the past few weeks.

On the political front, the main platform of exiled Syrian opposition factions confirmed as president Ahmad Jarba who is close to Saudi Arabia. The Syrian National Coalition stressed again on Monday it does not intend to participate in an international conference scheduled to take place in Switzerland on January 22 but confirmed an upcoming visit to Russia, a close Assad ally. (ANSAmed).