Ukrainian government forces closed in on the city of Donetsk as the military demanded pro-Russian separatists to surrender, according to The Associated Press.
Donetsk, a major industrial hub in Ukraine's Russian-speaking east, resonated with the crash of shells on its outskirts for about eight hours up to midday on Sunday, the AP reported. Donetsk, a once bustling metropolis of nearly one million people, is facing an increasing shortage of food, water and electricity.
To the east of Donetsk, government forces and the separatists were fighting for control of the town of Krasny Luch, a rail and road junction through which Kiev says the rebels are receiving supplies of Russian military equipment, the AP reported.
Talk of a ceasefire, a possibility raised by a separatist leader on Saturday, evaporated as Kiev government forces kept up an offensive to crush the rebels, according to the AP.
Ukrainian military spokesman Andriy Lysenko said if the rebels wanted a ceasefire this meant "raising white flags and putting down their guns," the AP reported. There would be no truce while the Ukrainian army continued "punitive" military action, the rebels retorted in a statement.
In the city's northern district of Putilovka, a building housing the offices of Ukrtelecom telecommunications company was ablaze, apparently hit by a shell, according to the AP.
Lysenko said in the past 24 hours, the military had "continued successful offensive operations, considerably tightening the circle around the capital of the Donbass, Donetsk", the AP reported. He added: "The (separatist) fighters are in panic and chaos. There are numerous cases of desertion among the terrorists."
Ukraine and its Western allies accuse Russia of orchestrating the separatist revolt which erupted in April after Russia's annexation of Ukraine's Crimea peninsula, according to the AP.
It says Russia is funnelling tanks and missile systems to the rebels, who have declared independent "people's republics" in the two main industrial regions. Moscow denies involvement, the AP reported.