By Weedah Hamzah & Shabtai Gold
Dozens of trucks laden with humanitarian aid have entered five besieged areas near the capital Damascus and north-western Syria.
"The operation is still ongoing," said Linda Tom, a spokeswoman for the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) in Amman, Jordan, without elaborating.
Trucks carrying food supplies entered Madaya, a rebel-held town about 25km northwest of Damascus, which has been under siege since July by forces loyal to Syrian President Bashar al-Assad, aided by fighters from the allied Lebanese Shiite Hezbollah movement.
UN sources said some trucks also entered the nearby town of Zabadani.
Earlier in the day some 35 trucks carrying aid entered Maadamiyat al-Sham in rural Damascus, state-run Syrian News Agency SANA reported.
The aid arrived a day after UN envoy Staffan de Mistura met Syrian Foreign Minister Walid al-Moallem to press for humanitarian access as well as steps towards a ceasefire.
The area has been under siege from government forces since 2012.
"Around six trucks of aid has also entered the besieged two villages of Foua and Kefraya," the head of the Britain-based Syrian Observatory for Human Rights, Rami Abdel Rahman, told DPA.
Foua and Kefraya are government-held Shiite towns under siege for nearly 10 months by opposition Sunni rebels in the north-western province of Idlib.
World powers meeting in Munich last week proposed a nationwide cessation of hostilities meant to come into effect this week, except for those targeting terrorist groups. There was no sign of progress on this front.
Syrian President Bashar al-Assad on Monday said he did not think the necessary conditions could be met within a week.
Meanwhile, 15 civilians were killed when US-led forces hit a bakery in an Islamic State-held town in the northeast, as people were lining up, activists said.
The strikes in Shaddadi coincided with an attack by the Kurdish People's Protection Units (YPG) against Islamic State in the area, Abdel Rahman said.
The YPG has been the main force pushing back the jihadists across northern Syria, aided by an intense US-led air campaign.
The Observatory also said hundreds of Islamic rebel fighters crossed the Turkish border on their way to the Azaz area in the northern countryside of Aleppo, where Kurdish fighters have been making advances.
Rebel groups in Aleppo are grappling with two simultaneous attacks -- one mounted by Kurdish forces from the west and another by the regime forces from the north.
Turkish President Recep Tayyip Erdogan said his military would continue to strike at the YPG in Aleppo province, where the Kurds have taken advantage of the Russian air campaign to advance against rebel forces.
Erdogan charged that the Kurds had attacked Turkey and repeated his call to the United States to choose between Turkey and the YPG.
Late Wednesday Israeli forces shelled a Syrian army position south of Damascus, the Observatory said.
Israel has been accused of previously hitting government positions and those of its Lebanese ally Hezbollah.