A Russian state TV journalist has been killed in a mortar attack near a village outside the east Ukrainian city of Luhansk, Russian media report.
Igor Kornelyuk died in hospital after the attack near Metalist while a colleague, sound engineer Anton Voloshin, was reported missing.
Meanwhile, a major pipeline in Ukraine carrying gas from Russia to the rest of Europe was hit by a blast.
However, European and Russian companies said gas exports were not affected.
The explosion hit the Urengoy-Pomary-Uzhgorod Pipeline, also known as the Trans-Siberian Pipeline, in Ukraine's north-east. No one was reported injured by the blast.
'Attempted terrorist attack'
It is not immediately clear what caused the blast. According to AFP news agency, Ukraine's state emergencies service said it appeared to have been the result of a puncture or loss of pressure.
However, the energy ministry said it could have been an "attempted terrorist attack", Reuters reported.
Ukraine's gas transport monopoly, a Slovak gas transit firm, and sources at Russian gas producer Gazprom, all told reporters that the transit of gas to Europe would not be affected.
Gas was being delivered through a parallel pipeline, a Gazprom source said.
Meanwhile, Moscow condemned the killing of journalist Igor Kornelyuk, describing it as a "crime of Ukrainian forces".
Italian photojournalist Andrea Rocchelli and prominent Russian human rights activist Andrey Mironov, who was accompanying him, were killed by mortar fire in eastern Ukraine last month.
Hundreds of lives have been lost in fighting in Ukraine's Luhansk and Donetsk provinces, where pro-Russian rebels are battling government forces after declaring independence just over a month ago.
Reports of three civilians killed overnight by a bombardment near the rebel-held town of Sloviansk, in Donetsk region, could not be verified independently.