U.S.-backed fighters pushed ahead in their offensive in northern Syria on Friday, getting closer to a stronghold of the Islamic State group, opposition activists said.
The predominantly Kurdish Syria Democratic Forces took at least four more villages on the way to the IS-held city of Manbij, according to two activist groups, the Britain-based Syrian Observatory for Human Rights and the Local Coordination Committee.
A Russia- and U.S.-brokered truce in Syria began on Feb. 27, but fighting has continued to rage in many areas, particularly around the city of Aleppo, trapping civilians in the cross-fire between government and opposition forces. Syria's 5-year civil war has left some 250,000 people dead.
On Wednesday, SDF fighters, aided by U.S.-led airstrikes, launched their offensive on Manbij, which is on a key supply route linking the Turkish border to the city of Raqqa, the extremist group's de facto capital.
Some 20 IS fighters and four from the SDF have been killed in three days of fighting, the Observatory said. It said that 28 villages are now under SDF control. The group said Abu Layla, the commander of one of the SDF factions known as Shams al-Shammal, was seriously wounded and evacuated to hospital in neighboring Iraq.
The fighting comes as the United Nations Security Council announced Friday it will formally ask Syria to allow humanitarian air drops to besieged areas. U.N. humanitarian chief Stephen O'Brien warned that access to millions of Syrians in need of help is worsening amid the violence.