- Civilians trapped in steel works under Russian siege
- Fighting reported along front in east, south
- 400 medical centres destroyed, damaged -Zelenskiy
- EU to tweak sanctions plan to win over eastern states -sources
Ukraine said a new attempt was under way on Friday to evacuate scores of civilians trapped in a heavily bombed steel works in the city of Mariupol, after bloody fighting with Russian forces thwarted efforts to bring them to safety the previous day.
Mariupol, a strategic southern port on the Azov Sea, has endured the most destructive siege of the 10-week-old war and the sprawling Soviet-era Azovstal steel plant is the last part of the city still in the hands of holdout Ukrainian fighters.
UN-brokered evacuations of some of the hundreds of civilians who had taken shelter in the plant's network of tunnels and bunkers began at the weekend, but were halted in recent days by renewed fighting.
"The next stage of rescuing our people from Azovstal is under way at the moment. Information about the results will be provided later," said Andriy Yermak, head of the Ukrainian presidential staff. He gave no more details.
Russia has turned its heaviest firepower on Ukraine's east and south, after failing to take the capital Kyiv in the early weeks following its 24 Feb. invasion. The new front is aimed at limiting Ukraine's access to the Black Sea, vital for its grain and metals exports, and linking Russian-controlled territory in the east to the Crimea Peninsula, seized by Moscow in 2014.
Moscow calls its actions a "special military operation" to disarm Ukraine and rid it of anti-Russian nationalism fomented by the West. Ukraine and the West say Russia launched an unprovoked war of aggression. More than 5 million Ukrainians have fled abroad since the start of the invasion.
Ukraine's general staff said on Friday that Russian forces were continuing their "attempts to fully take over the Donetsk and Luhansk regions", areas in the east partially seized by Moscow-backed separatists in 2014.
Russia's defence ministry said it had destroyed a large ammunition depot in the eastern Ukrainian city of Kramatorsk in a missile strike. It also said its air defences shot down two Ukrainian warplanes in the Luhansk region.
It was not possible to independently verify either side's statements about events on the battlefield.
Ukrainian officials have said Russia might step up its offensive before May 9, when Moscow commemorates the Soviet Union's victory over Nazi Germany in World War Two.
Ukrainian President Volodymyr Zelenskiy said on Thursday that nearly 4000 hospitals and other medical facilities in the country had been destroyed on damaged since the invasion.
"This amounts to a complete lack of medication for cancer patients. It means extreme difficulties or a complete lack of insulin for diabetes," Zelenskiy said in a video address to a medical charity group. "It is impossible to carry out surgery. It even means, quite simply, a lack of antibiotics."
The Kremlin says it targets only military or strategic sites and not civilians. Ukraine daily reports civilian casualties from Russian shelling and fighting, and accuses Russia of war crimes. Russia denies the allegations.
In Mariupol an estimated 200 civilians remained trapped underground in the Azovstal plant with little food or water.
Russian President Vladimir Putin has said Russia was prepared to provide safe passage for the civilians but reiterated calls for Ukrainian forces inside to disarm.
Putin declared victory in Mariupol on 21 April and ordered his forces to seal off the plant.
The Kremlin denies Ukrainian allegations that Russian troops stormed the plant in recent days and said humanitarian corridors were in place. Russia's military promised to pause its activity for the next two days to allow civilians to leave.
Aerial footage of the plant, released on Thursday by Ukraine's Azov Regiment, showed three explosions striking different parts of the vast complex, which was engulfed in heavy, dark smoke. Reuters verified the footage location by matching buildings with satellite imagery, but was unable to determine when the video was filmed.
The stubborn Ukrainian defence of Azovstal has underlined Russia's failure to take major cities in a war that has united Western powers in arming Kyiv and punishing Moscow with the most severe sanctions ever imposed on a major power.
Economic measures from Washington and European allies have hobbled Russia's $1.8 trillion economy while billions of dollars worth of military aid has helped Ukraine frustrate the invasion.
In an apparent crack in Western unity, however, Hungarian Prime Minister Viktor Orban said on Friday his country could not support the European Union's proposed new sanctions package, which includes an oil embargo, in its present form.
Orban said the European Commission's current proposal would amount to an "atomic bomb" dropped on the Hungarian economy, adding that Hungary was ready to negotiate.
Three sources later told Reuters that the EU executive would amend its proposal, extending the period before the embargo took effect for Hungary, Slovakia and the Czech Republic to give the more time to upgrade their own oil infrastructure.
The Kremlin has said Russia is weighing responses to the EU plan.