Ukraine says it has recaptured ground in Bakhmut, a rare advance after months of grinding Russian gains in the eastern city.
EDnews informs via BBC that Kyiv said its forces advanced 2km (1.2 miles) in a week. Russia said its troops had regrouped in one area.
The claims signal a momentum shift in Bakhmut - but more widely, there is no clear evidence of an Ukrainian counter-offensive.
However, two explosions were reported on Friday in Russian-occupied Luhansk.
Images posted on social media, verified by the BBC, show a big plume of black smoke rising from the city, which lies about 90km (55.9 miles) behind the front line in eastern Ukraine.
The blasts come a day after the UK said it had supplied Ukraine with long range Storm Shadow cruise missiles.
Kremlin-appointed officials said six children in Luhansk were injured in a missile attack alongside Russian parliamentarian Viktor Vodolatsky. The authorities there have blamed the attack on Kyiv.
Luhansk is beyond the reach of the Himars rockets Ukraine has previously relied on for deep strikes against Russian targets.
But Russian-appointed officials in the region said they thought Ukrainian-made missiles were responsible, hitting administrative buildings of two defunct enterprises.
Earlier Russia's defence ministry said Russian troops in one Bakhmut area had changed their position for strategic reasons.
It said units of the southern group of Russian forces had taken up a better defensive position in the Maloilinivka area, something which took into consideration "the favourable conditions of the Berkhivka reservoir".
However the head of Russia's Wagner mercenary group Yevgeny Prigozhin said what the Ministry of Defence was talking about "is unfortunately called 'fleeing' and not a 'regrouping'".
As the intense, bloody battle has worn on, Bakhmut has become symbolically important - though many experts question its tactical value.
In a post on Telegram, Deputy Defence Minister Hanna Malyar claimed Russia suffered significant troop losses as Ukraine gained 2km without losing any positions.
Meanwhile Russian military bloggers reported Ukrainian advances or troop movements in several areas.
