A senior U.S. defense official reportedly said that Russian troops are advancing towards the Ukraine capital city of Kyiv on Thursday.

According to CNN and Reuters, the official said that the Russian government continues to send troops into Ukraine.

The official reportedly said that Russia launched more than 160 missiles. Most were short-range ballistic missiles, but some were medium-range and cruise missiles.

The official said, however, that it is impossible to confirm media reports that Russia has seized control of the Chernobyl nuclear power plant site.

Meanwhile, about 220 Ukrainians were reportedly killed or wounded on the first day of the Russian invasion.

Ukraine’s health minister Viktor Lyashko said 57 Ukrainians were killed and 169 more were wounded on Thursday.

The Russian defense ministry claimed that Russia has disabled 83 ground military facilities in Ukraine after strikes, but did not attack cities or non-combat facilities within military bases in order to prevent casualties.