A "humanitarian pause" in the Syrian army's Russian-backed assault on Aleppo took effect Thursday, but despite a drop in violence there was little sign residents were heeding calls to leave.
Moscow said the truce would be extended by 24 hours, and the U.N. said it hoped to carry out the first medical evacuations from Aleppo on Friday, after getting clearance from all warring parties.
Despite the lull, NATO chief Jens Stoltenberg expressed concern that a Russian aircraft carrier battlegroup, on its way from the North Sea and currently off the coast of Britain, could join attacks on Aleppo.
The unilateral ceasefire began at 8:00 am (0500 GMT) with the aim of allowing civilians and fighters to evacuate the city's opposition-controlled east.
Shortly after the pause began, gunfire and artillery exchanges erupted around one crossing point, with state news agency SANA saying "terrorist groups" had targeted the area "in an attempt to hinder the humanitarian pause".
But by afternoon, the clashes had subsided and the east was calm, though the streets were empty.
The truce was initially described as lasting just 11 hours, but Russia's Defense Minister Sergei Shoigu announced Thursday afternoon it would be extended.