Russia fired two missiles at kyiv on Thursday during a visit by UN Secretary-General Antonio Guterres, Ukrainian officials said, as Moscow pressed an assault in the east that drew fresh US pledges of aid military and humanitarian.

The rockets rocked the central district of Shevchenko in the Ukrainian capital and one of them hit the lower floors of a 25-storey residential building, injuring at least 10 people, Ukrainian officials said. Reuters witnesses reported hearing two explosions, but their cause could not be independently verified. There were no Russian comments on the explosions.

A Ukrainian serviceman walks beside a combat vehicle, outside kyiv, Ukraine. (AP, file)

Russia withdrew its invasion forces near kyiv in early April after failing to capture the city, which has since received visits from senior officials from the United States and its European allies. But Thursday’s outbursts, heard shortly after talks between Guterres and Ukrainian President Volodymyr Zelenskyy ended, highlighted concerns that kyiv still remains vulnerable to heavy Russian weapons.

“There was an attack on Kyiv…it shocked me, not because I’m here, but because Kyiv is a sacred city for Ukrainians and Russians alike,” António Guterres told the channel. Portuguese television RTP, questioned about the explosions. Zelenskyy said the blasts “proved that we shouldn’t lower our vigilance. We shouldn’t think the war is over.”

Guterres’ talks with Zelenskyy focused in part on evacuating Ukrainian fighters and civilians trapped in a steel mill in the besieged southeastern city of Mariupol, Russia’s main target in the eastern region of the country. Donbass.

Russian President Vladimir Putin agreed in principle to the involvement of the UN and the Red Cross in the evacuation of the factory during talks in Moscow with António Guterres on Tuesday.