BEIRUT — Kurdish fighters backed by Russian airstrikes launched an attack in northern Syria on Wednesday in an attempt to capture a military air base held by Syrian insurgents, activists and a rebel commander said.
Syria's Kurds have been among the most effective forces battling the Islamic State group, but have remained largely neutral in the conflict between President Bashar Assad and the rebels fighting to overthrow him.
But with Syrian troops backed by Russian warplanes waging a major offensive between the northern city of Aleppo and the Turkish border, the Kurds appeared to be exploiting the chaos to expand their nearby Afrin enclave.
Maj. Yasser Abdul-Rahim, a rebel commander in the northern province of Aleppo, told The Associated Press that fighters from the Kurdish People's Protection Units, known as the YPG, are clashing with rebels near Mannagh air base. He accused the YPG of trying to take Arab villages near Afrin.
"We are fighting on three fronts," he said via Skype, referring to the YPG, Syrian troops and the Islamic State group, which also controls parts of Aleppo province. He warned that Mannagh air base could fall to Kurdish fighters because of the Russian air cover and the intensity of the attack.
The Britain-based Syrian Observatory for Human Rights said YPG fighters are trying to capture the former Syrian army air base, which fell to the opposition in August 2013.
Ahmad al-Ahmad, an opposition activist based in Aleppo province, said the fighting is concentrating outside the air base and that Russian warplanes are bombarding the area. He said that YPG fighters are also trying to push their way toward the nearby village of Kfar Naya. "The front in northern Aleppo is in flames," he said via Skype.
Kurdish forces in Afrin could not immediately be reached for comment.
The Observatory's chief Rami Abdurrahman said that since the offensive in Aleppo province began on Feb. 1, some 518 people have been killed, including 101 civilians, 169 insurgents and 143 troops and pro-government forces. He said the dead include 105 members of al-Qaida's branch in Syria, the Nusra Front, and foreign jihadis.
Troops have captured dozens of villages in the area and were able to lift a three-year siege on two Shiite villages in Aleppo province last week.
Earlier in the day, Syria's state news agency SANA said opposition gunmen opened fire on aid vehicles in the besieged rebel-held town of Madaya, near the capital Damascus, but no casualties were reported.
An official with the Syrian Arab Red Crescent said Wednesday that the convoy, which included vehicles from the SARC and the International Committee of the Red Cross, was evacuating sick people from Madaya when it came under fire by unknown gunmen.
The official, who spoke on condition of anonymity in line with regulations, said the operation had been completed and the people were successfully evacuated.
Madaya, which has been besieged by government forces and allied militiamen for months, gained international attention after harrowing pictures emerged showing emaciated children and starving residents.
SANA said the shooting occurred late Tuesday night, delaying operations for several hours.
Syria's conflict has killed more than 250,000 people and displaced millions since the uprising began in March 2011.
Associated Press writer Albert Aji contributed to this report from Damascus, Syria.