Ukraine official says assault halts evacuations

A second attempt to evacuate civilians from a besieged city in southern Ukraine collapsed on Sunday as Russian attacks stopped plans to create a humanitarian corridor, a government official said.

Food, water, medicine and almost all other supplies were in desperately short supply in the port city of Mariupol, where Russian and Ukrainian forces had agreed to a 11-hour cease-fire to allow civilians and the wounded to be evacuated.

The conflict, now in its 11th day, has caused 1.5 million people to flee the country, with head of the UN refugee agency calling the exodus "the fastest-growing refugee crisis in Europe since World War II."