KYIV (Reuters) -Russia's military pressed on with fierce assaults on the eastern Ukrainian town of Avdiivka on Saturday, with shelling so fierce that emergency crews were unable to recover the dead from wrecked buildings, the town's top administrative official said.
It was the fifth straight day of assaults on the town in Ukraine's industrial heartland of Donbas, focal point of Moscow's 19-month-old invasion of its neighbour.
Both Russia and the United States have described the upsurge in violence around Avdiivka as a new Russian offensive.
Fighting intensified in other sectors of the 1,000-km-long (600-mile) front. One top Ukrainian commander said clashes further north had "significantly worsened", while another said Russian losses were mounting in the war's southern sectors.
Vitaliy Barabash, head of Avdiivka's military administration, said residents had experienced a rare overnight respite from air strikes, but attacks had resumed at daybreak.
"They are striking with everything they have. Bouts of shooting, artillery, multiple rocket launchers, mortars and a lot of aircraft," Barabash told national television.
All rescue operations had been halted, he said, amid reports of people believed to be trapped under rubble of buildings levelled by shelling and air strikes.
"Operations cannot take place in such conditions. It is frightening to leave because the road is under fire. And no easier to stay as there is no place, no basement that can withstand the strikes."
Barabash said 1,620 residents remained in Avdiivka, a town with a large coking plant and a pre-war population of 32,000.
Oleksandr Stupun, a military spokesperson, said Avdiivka was important for Moscow "because it is the only chance to show some kind of victory. They have no other options."
Russian forces in the area, he told national television, "have been increasing for four days in a row. That's why the enemy is taking revenge on the civilian population."
The town, 20 km (12 miles) west of the Russian-held town of Donetsk, has become a watchword for resistance. It held off attacks in 2014 when Russian-backed separatists seized areas of eastern Ukraine and has undergone serious fortification since.
A four-month-old Ukrainian counteroffensive has made some progress in both the east, near the shattered city of Bakhmut, taken by Russian troops in May, and in the south, where Kyiv hopes to reach the Sea of Azov. But gains have been incremental.
Oleksandr Syrskyi, commander of Ukraine's ground forces, visited troops near Kupiansk further north and said Russian forces had regrouped after suffering losses.
"The main objective of the enemy is the defeat of a grouping of our troops, the encirclement of Kupiansk and to reach the Oskil River," a military platform quoted him as saying.
A four-month-old Ukrainian counteroffensive has made some progress in the east, near Bakhmut, and in the south, where Kyiv hopes to reach the Sea of Azov, but gains have been incremental.
General Oleksandr Tarnavskyi, head of forces in the south, wrote on Telegram that Ukrainian troops were advancing southward and Russian casualties were "continuing to rise".
(Reporting by Dan Peleschuk, Ron Popeski and Maria Starkova; Editing by Helen Popper and Daniel Wallis)