Here are the latest developments in the war in Ukraine:

– Russia threatens Kyiv –

A Ukrainian military factory outside Kyiv is partially destroyed by overnight Russian strikes, AFP reports, as Moscow warns it will intensify attacks on the capital in response to Ukrainian strikes on Russian soil.

Russian officials accuse Ukraine of sending two helicopters across the border to bomb a town in Russia’s southern Bryansk region, wounding eight people. Ukraine has denied the accusations.

The military factory outside Kyiv produced missiles allegedly used to hit Russia’s Moskva warship.

“The number and scale of missile strikes against targets in Kyiv will increase in response to any terrorist attacks or sabotage committed by the Kyiv nationalist regime on Russian territory,” the defence ministry in Moscow says.

– Five million flee Ukraine –

More than five million people have now fled Ukraine since the Russian invasion on February 24, the United Nations says.

The UN’s refugee agency lists 4,796,245 million Ukrainians who have crossed the borders, while its International Organization for Migration says nearly 215,000 third-country nationals have also left.

– Russian flagship sinks –

Russia’s guided-missile cruiser Moskva sinks in the Black Sea after being damaged, Russia’s defence ministry says.

“While being towed… towards the destination port, the vessel lost its balance due to damage sustained in the hull as fire broke out after ammunition exploded. Given the choppy seas, the vessel sank,” the state news agency TASS quotes the ministry as saying.

Pentagon spokesman John Kirby says the sinking of the Moskva dealt a “big blow” to the Black Sea fleet.

– Russia warns Finland, Sweden –

Russia’s foreign ministry warns of unspecified “consequences” should non-aligned Finland and Sweden join NATO.

Moscow’s military actions in Ukraine have sparked a dramatic U-turn in public and political opinion in both countries. Finland said this week it will decide whether to apply for NATO membership within weeks, and Sweden is also discussing joining the alliance.

– ‘Polish mercenaries’ killed –

Russia’s defence ministry says it has killed up to 30 Polish mercenaries fighting for Ukrainian forces in the northeastern region of Kharkiv.

Its says strategic rocket forces “eliminated up to 30 Polish mercenaries” in a strike on the village of Izyumskoe, not far from the city of Kharkiv.

– Deaths in east –

Ukraine says Russian strikes have killed five people in the east of the country after President Volodymyr Zelensky warned Moscow’s forces were aiming to “destroy” the region.

Two people died killed and two more wounded in the eastern Lugansk region while another three were killed and seven wounded in the neighbouring Donetsk region, the Kyiv presidency says.

Seven people were also killed and more than two dozen injured in a Russian attack on buses ferrying civilians from the east of the country, the office of Ukraine’s prosecutor general says.

– CIA nuclear warning –

Russia’s setbacks could lead President Vladimir Putin to resort to using a tactical or low-yield nuclear weapon, CIA director William Burns says.

“Given the potential desperation of President Putin and the Russian leadership, given the setbacks that they’ve faced so far, militarily, none of us can take lightly the threat posed by a potential resort to tactical nuclear weapons or low-yield nuclear weapons,” Burns says.

– Kharkiv offensive –

At least 503 civilians have been killed in Ukraine’s eastern Kharkiv region since Russia launched its invasion on February 24, the local governor Oleg Synegubov says.

He writes on Telegram that the dead included 24 children.