Ukraine and Russia: What you need to know right now

* Russia said it used a diesel submarine in the Black Sea to strike Ukrainian military targets with Kalibr cruise missiles, the first time Moscow has announced the use of its submarine fleet to hit its neighbour. * Ukrainian President Volodymyr Zelenskiy's office said Russia was pounding the entire front line in the eastern Donetsk region with rockets, artillery, mortar bombs and aircraft.

Ukraine acknowledged on Friday it was taking heavy losses in Russia's assault in the east, but said Russia's losses were even worse, as U.S. President Joe Biden called on Congress to send as much as $33 billion to help Kyiv withstand the attack. FIGHTING AND CASUALTIES

* A journalist from the U.S.-backed broadcaster Radio Liberty was killed in a Russian missile attack that hit her apartment building in Kyiv in what a Ukrainian government official said was an act of Russian "barbarism". * Russia said its missiles fired at Kyiv destroyed the production facilities of a space-rocket plant.

* Ukraine has suffered serious losses in the war with Russia but Moscow's forces have lost many more soldiers, an aide to Zelenskiy said in a video posted online. * Russia said it used a diesel submarine in the Black Sea to strike Ukrainian military targets with Kalibr cruise missiles, the first time Moscow has announced the use of its submarine fleet to hit its neighbour.

* Ukrainian President Volodymyr Zelenskiy's office said Russia was pounding the entire front line in the eastern Donetsk region with rockets, artillery, mortar bombs and aircraft. The Ukrainian general staff said Russia was shelling positions along the line of contact to prevent the Ukrainians from regrouping. * Moscow regards winning the "Battle for Donbas" as crucial if it is to achieve its stated objective of securing control over the Donetsk and Luhansk regions in the east, Britain's defence ministry said. "Fighting has been particularly heavy around Lysychansk and Severodonetsk, with an attempted advance south from Izium towards Sloviansk," it said on Twitter.

A border checkpoint at a village in Russia's Bryansk region bordering Ukraine came under mortar fire from Ukrainian territory, the regional governor said on Friday. Reports of battlefield developments could not be immediately verified by Reuters.

WEST'S RESPONSE * Germany is looking into sending self-propelled howitzers to Ukraine, a security source told Reuters on Friday, a day after U.S. President Joe Biden presented a $33 billion plan for weapons, ammunition and other aid to Ukraine.

* NATO is ready to maintain support for Ukraine for years in the war against Russia, Secretary-General Jens Stoltenberg said. * The U.S. mission to the OSCE said the Kremlin might attempt "sham referenda" in southern and eastern areas it had captured since the Feb. 24 invasion, using "a well-worn playbook that steals from history’s darkest chapters".

HUMAN AND ECONOMIC IMPACT * In the southeastern port city of Mariupol devastated by a Russian siege, residents recounted the horrors of the battle as they sifted through rubble for belongings, cooked meals by the roadside or just stared at the charred shells of buildings around them.

* After consultations with U.N. Secretary General Antonio Guterres, Ukraine said it hoped on Friday to evacuate civilians in Mariupol holed up in a vast steel works along with the last defending Ukrainian troops. * The bodies of 1,150 civilians have been recovered in Ukraine's Kyiv region since Russia's invasion and 50-70% of them had bullet wounds from small arms, Kyiv police said.

* Britain said on Friday it was sending experts to help Ukraine with gathering evidence and prosecuting war crimes, with a team due to arrive in Poland in early May. QUOTE

* "It was a massacre. It was the scariest thing when the shells were flying overhead. Shells, rounds and all such, you couldn't survive it. And yet we did," said Vitaliy Kudasov, 71, a resident of shattered Mariupol. (Compiled by Mark Heinrich)