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UN aid chief Martin Griffiths on Monday said humanitarian teams were ramping up support for civilians in the Ukrainian cities of Mariupol, Kharkiv and Kherson, which are among the areas worst hit by Russia’s military advance.
The UN’s top humanitarian and emergency relief co-ordinator said more than 400 civilians have been killed during Russia’s invasion of Ukraine and 800 more have been injured, though it is believed the actual figure is “considerably higher”.

About 1.7 million refugees have already fled the country in only 11 days of fighting and many more are set to follow, said Mr Griffiths. The UN was scaling up support to bring food and funds to Ukrainian civilians.
“Millions of lives have been shattered,” Mr Griffiths told the UN Security Council.
“People cannot stay home with shops shut, power and water cut, shells falling and phones switched off. They can’t find what they need even if they have money to pay for it. As we have seen even as the TV cameras roll, many can’t even flee in safety either.”
Lana Nusseibeh, the UN ambassador for the UAE, which holds a temporary seat on the council, said Ukraine's crisis had hit "catastrophic levels" and called for greater efforts to end fighting and "urgently alleviate humanitarian suffering".
Diplomats met in New York against a backdrop of deepening violence in Ukraine, where officials say a Russian air strike on Monday hit a bread factory in the north, killing at least 13 civilians, even as nascent peace talks between Kyiv and Moscow made little headway.
France and Mexico last week unveiled plans for a UN Security Council resolution to address the humanitarian impact, but it remains unclear whether it will be acceptable to Russia, a permanent member that can veto council decisions.
Mexico’s UN ambassador Juan Ramon de la Fuente Ramirez told reporters on Monday that the draft document was aimed at authorising “all means to get humanitarian aid in soon and to all who need it”.
A vote on the draft has yet to be scheduled.
The UN has been at the vanguard of diplomatic efforts to isolate Russia over its invasion of Ukraine. Russia has called the campaign it launched on February 24 a “special military operation” to oust a “Nazi” government in Kyiv.
UN humanitarians have met in Moscow with officials from Russia’s Ministry of Defence to bring “rapid, life-saving assistance to the most vulnerable people in Ukraine”, UN spokesman Stephane Dujarric told reporters on Monday.