Clutching empty plastic bottles, hundreds of people stand waiting for water in this besieged city, with the almost constant thud of artillery shells echoing in the distance.

More than two months after pro-Russian separatists rose up in east Ukraine, electricity and water have been cut off in this depressed industrial city, food is running low and half the population has fled.

Many of those who remain are getting desperate and local officials, echoed by Russia, warn that a humanitarian disaster is looming in east Ukraine despite a unilateral cease-fire set by Kiev between the rebels and government forces trying to pry them out.