(Reuters) - Swiftly advancing Ukrainian troops were bearing down on the main railway supplying Russian forces in the east on Friday, after the collapse of a section of Russia's front line caused the most dramatic shift in the war's momentum since its early weeks.

FIGHTING

* President Zelenskiy said in a Thursday evening address that Ukrainian forces had reclaimed 1,000 square km (385 square miles) of territory in the south and east since Sept. 1.

* The Ukrainian general staff said early on Friday its forces had advanced almost 50 km in three days and that retreating Russian forces were trying to evacuate wounded personnel and damaged military equipment.

* The Institute for the Study of War think tank said the Ukrainians were now within just 15 km of Kupiansk, an essential junction for the main railway lines that Moscow has been using for months to supply its forces on the battlefields in the east.

* A Russian air strike hit a hospital in Ukraine's northeastern region of Sumy on Friday morning, destroying the building and causing casualties, the region's governor said. Russia denies targeting civilians.

* Reuters was not immediately able to verify the reports.

ENERGY

* European Union energy ministers met on Friday to seek agreement on ways to shield citizens from sky-high energy prices and prevent power utilities from collapsing as Russia has restricted gas supplies to Europe in the standoff over Ukraine.

* EU diplomats say member states broadly back proposals to help power providers from being crushed by a liquidity crunch due to high energy prices but are divided about plans to cap the price of gas from Russia.

* European Union countries should be able to agree on the bloc's proposal to skim excess revenues from non-gas power generators and use the cash to curb consumer bills, Luxembourg's energy minister said.

* VNG VNG.UL, one of Germany's biggest importers of Russian natural gas, asked the government for aid to stay afloat, the latest European energy firm to request state support in response to plummeting Russian supplies.

* The price cap that G7 countries want to impose on Russian oil to punish Moscow should be set at a fair market value minus any risk premium resulting from its invasion of Ukraine, a U.S. Treasury Department official told reporters.

* Russia's top lawmaker said Western plans to introduce a price cap on Russian oil and gas exports would fail and prices would soar far beyond it.

GRAIN

* Russia's Foreign Ministry said the deal to unblock Ukrainian grain exports via the Black Sea is being fulfilled "badly" and its extension, due in late November, will depend on how it is implemented, RIA reported. The White House said earlier that Washington sees no sign the deal is unravelling.

SANCTIONS

* The United States on Thursday imposed sanctions on an Iranian company it accused of coordinating military flights to transport Iranian drones to Russia and three companies it said were involved in the production of Iranian drones. Iran has denied supplying drones to Russia.

* Russia demanded at the United Nations on Thursday that the United States and Britain provide evidence to support their allegations that Moscow was seeking drones from Iran and rockets and artillery shells from North Korea to use in Ukraine.