REUTERS, Chasiv Yar

Ukrainian forces hung on to positions in the ruined eastern city of Bakhmut yesterday, while Moscow said its security forces had battled Ukrainian saboteurs who had taken hostages in a cross-border raid.

Russia’s FSB security force said the situation was now “under control” in Bryansk province just north of the Ukrainian border. Earlier Moscow had said armed Ukrainians had crossed the frontier, fired on a car killing one person and wounding a child, and held hostages in a shop.

In a brief television address, President Vladimir Putin said the attackers had fired deliberately on the car, knowing it held civilians.

“They won’t achieve anything. We will crush them,” he said, saying Russia was fighting “terrorists and neo-Nazis”.

An aide to Ukrainian President Volodymyr Zelensky called the reports a false provocation by Moscow, but also appeared to imply some form of incident had been carried out by partisans.

Near the front lines west of Bakhmut, in the Ukrainian-held town of Chasiv Yar, the thump of outgoing artillery fire could be heard.

In nearby towns and villages, new trenches had been dug on the roadside 20-40 metres (65-130 feet) apart, an apparent sign that Ukrainian forces were strengthening defensive positions west of the city.

Residents trickled out of the area, carrying bags. “We remained until the very last. We wanted to stay. But we how can we? Our neighbour’s flat has now been destroyed. It is time to go,” said Svitalana, 47.

The boss of Russia’s Wagner private army, Yevgeny Prigozhin, released video of his men waving a Wagner banner and musical instruments atop a ruined multi-storey building, which he said had been filmed near the centre of Bakhmut.

Bakhmut has been reduced to a blasted wasteland, with a few thousand of its 70,000 pre-war civilian population still inside as armies battle street-by-street.

Meanwhile, Russian missiles crashed into a five-storey apartment block in the southern city of Zaporizhzia overnight, collapsing upper floors in the centre of the building.

As dawn broke, Reuters journalists saw rescue workers carry the body of a man out of the wreckage. Police said at least four people had been killed.

An international team of war crimes investigators said yesterday the Russian state had funded and operated a network of at least 20 torture chambers during its eight-month occupation of Kherson, recaptured last year by Ukrainian forces.

Russia’s aim was to “subjugate, re-educate or kill Ukrainian civic leaders and ordinary dissenters”, the team said.