Damascus, May 25 (IANS) Several bombings rocked positions of the US-backed rebels in northern Syria on Wednesday, a monitor group reported.
A powerful blast rocked the rebel-held city of Azaz in Syria's Aleppo province, near a base for US-backed militant groups, Xinhua quoted the Syrian Observatory for Human Rights as saying.
The Britain-based watchdog group said four fighters were killed in the blast and many more were wounded.
Meanwhile, Kurdish activists said a car bomb was detonated near the base, which belongs to the Northern Storm Brigade in Azaz, killing one of the field commanders of the group, known as Omar Farah.
An explosive device tore through a vehicle of the US-backed Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab fighters, in the province of al-Hasakah, leaving unknown number of casualties among the SDF forces, according to the observatory.
In the province of Idlib, one person was injured when a car bomb went off near a bakery in the city, said the Britain-based watchdog group, spelling no further details.
No group has claimed responsibility for the attacks, but the bombings held the hallmark of the Islamic State (IS) group, which has recently felt threatened by the US and its allied rebel fighters on ground, particularly the SDF.
The SDF and allied militant groups unleashed a military campaign against the northern countryside of Al-Raqqa on Tuesday, just days after the US and the SDF put forward a plan for capturing the IS capital.
The observatory said over 20 IS fighters were killed on the first day of the battles in northern al-Raqqa.
The SDF managed to capture one town in northern al-Raqqa on Wednesday, known as Mistamraj, following intense battles with the IS.
The observatory, which relies on a wide network of activists on ground, said the battles in northern al-Raqqa are incessant.
The fighters started moving toward northern al-Raqqa from the southern countryside of the border city of Tal Abyyad and the countryside of Ein Issa in the northwestern rim of al-Raqqa, which fell to the IS in late 2013.
General Joseph Votel, head of US Centcom, secretly visited northern Syria on Friday for 11 hours, during which he met commanders of the SDF and other US-backed rebel groups, including the Liwa Thuwar al-Raqqa.
The visit was aimed to coordinate the US-led coalition and rebel plans in taking back Syria's northern province of Raqqa.
Pan-Arab al-Mayadeen TV said in a special report on Sunday that a plan for unleashing an attack on al-Raqqa was put forward during the meeting.
According to sources familiar with the situation, the TV said the attack was going to be launched with the participation of 12,000 fighters.
The conferees also discussed the requirements of the military offensive and the needs of the fighting groups, said the report.
An agreement was reached to focus on the Arab fighters who will attack to alleviate the fears of Turkey from any expansion of Kurdish fighters near the Turkish borders.
It said the meeting between Votel and the rebels came just days after a meeting between the Brett H. McGurk, US Special Presidential Envoy for the Global Coalition to Counter IS, and Saleh Muslim, head of the Kurdish Democratic Union in the countryside of Ayn al-Arab.
The report said the meeting discussed the same issue.
The 500 US soldiers, who have recently crossed into Kurdish areas in northern Syria, will directly take part in al-Raqqa battle, said the report.
Even though the timing of the battle was not declared at the time, the IS seemed to have anticipated the move, asking civilians in key areas in Raqqa to move toward IS-controlled towns in the countryside of that province.
Reports said the terror group also went on arrest raids for young men to oblige them to fight among its ranks.
