Electricity and water supplies have been knocked out in much of the rebel-held city of Luhansk in eastern Ukraine and a major oil refinery is on fire, Russian and Ukrainian media report.
Shelling has continued as Ukrainian forces try to advance against the pro-Russian rebels.
The shelling damaged an electricity substation in a district of Luhansk.
There is no sign of a ceasefire despite the crash of a Malaysian airliner in rebel-held territory on Thursday.
The jet with 298 people on board crashed between Krasni Luch in Luhansk region and Shakhtarsk in Donetsk region.
An oil refinery in Lisichansk, in Luhansk region, is ablaze, the Russian news agency RIA reports. News and pictures of the fire also came on Twitter on Friday, though the cause was not immediately clear.
Almost all of the city of Luhansk lacks water and electricity – the result of shells damaging an electricity substation in Kamennobrodsky district, the Russian news website Lenta.ru reports.
The Ukrainian news agency Unian, quoting a Luhansk city council statement, said the power cut had brought water pumping stations to a standstill.
