Ukraine and Russia: What you need to know right now

Reuters could not independently verify battle reports in Sievierodonetsk. * Russia has handed over the bodies of 210 Ukrainian fighters, most of whom who died defending the city of Mariupol from Russian forces at a vast steel works, the Ukrainian military said.

Ukrainian forces struggled to hold their ground in bloody street-to-street fighting in the eastern frontline city of Sievierodonetsk as President Zelenskiy said the situation was difficult, also pledging to retake Russia's gains. FIGHTING

* Moscow's forces do not control Sievierodonetsk, the governor of Luhansk region said. * Another Sievierodonetsk official said Ukrainian forces were in control of the industrial zone and the Azot chemical plant. Reuters could not independently verify battle reports in Sievierodonetsk.

* Russia has handed over the bodies of 210 Ukrainian fighters, most of whom who died defending the city of Mariupol from Russian forces at a vast steel works, the Ukrainian military said. * More than two weeks since a siege of the southern city of Mariupol ended, Tass news agency cited a Russian law enforcement source as saying that over 1,000 Ukrainian soldiers who surrendered there have been transferred to Russia for investigation.

* Russian shelling destroyed the warehouses of one of Ukraine's largest agricultural commodity terminals in the Black Sea port of Mykolaiv last weekend, the head of the region said. His account could not be independently verified. * Russian Defence Minister Sergei Shoigu said the Ukrainian ports of Mariupol and Berdyansk, seized by Russian forces, had been de-mined and were ready to resume grain shipments.

ECONOMY * Ukraine could export a maximum of only 2 million tonnes of grains a month if Russia refuses to lift its blockade of the country's Black Sea ports, Ukraine's first deputy minister for Agrarian Policy and Food said.

* The Russian and Turkish defence ministers discussed a potential grain exports corridor from Ukraine and northern Syria, Turkey's defence ministry said. Ukraine's embassy in Ankara said Ukraine was exerting "maximum effort" to lift blockades on its ports, but added there was no agreement yet between Ukraine, Russia and Turkey. * The World Bank board approved $1.49 billion in additional financing for Ukraine. It was part of a $4 billion pledge and will pay government and social workers' wages.

NUCLEAR * Radiation detectors in the Exclusion Zone around Ukraine's defunct Chornobyl nuclear power plant are back online for the first time since Russia seized the area on Feb. 24, and radiation levels are normal, the U.N. nuclear watchdog said. (Compiled by Grant McCool)