Loud explosions heard in central Kyiv

Two loud blasts were heard in central Kyiv early Friday, a journalist said, as Russian troops pushed closer to the Ukrainian capital in an invasion of its Western-backed neighbour.

Ukraine's army said that Russia fired on civilian areas of Kyiv but that Ukraine's air defence systems repelled "two deadly gifts", according to a post on its verified Facebook page.

Kyiv mayor Vitaly Klitschko said three people were injured with one in critical condition after "missile debris" hit a residential building.

He tweeted a photo showing a building with part of its wall torn down and firefighters present at the scene.

Russian missiles and shelling rained down on Ukrainian cities on Thursday after President Vladimir Putin unleashed a full-scale ground invasion and air assault, forcing civilians to shelter on metro systems.

Russia's forces pressed deep into Ukraine as deadly battles reached the outskirts of Kyiv and the West responded with punishing sanctions.

On Thursday, Russian paratroopers wrested control of the Gostomel airfield, on the northwestern outskirts of Kyiv, after swooping in with helicopters and jets from the direction of Belarus.

Ukraine's President Volodymyr Zelensky warned Friday that Russian "sabotage groups" have entered Kyiv and urged citizens to remain vigilant.