Video footage of Russia jet attacking civilian tower | Russia and Ukraine crisis

Ukraine's army is trying to repel a full-scale Russian invasion, with fierce battles taking place close to the capital Kyiv.

Fighting is raging at an airfield on the outskirts of the city, and it could become a springboard for the Russian army into Kyiv if its troops seize it.

The Russian assault is being fought on several fronts after it attacked from the east, north and south on Thursday.

Kyiv has been hit by blasts, and at least one block of flats was damaged.

Ukrainian officials said there had been missile strikes on the city, and there are reports that an aircraft was brought down.

Ukraine says dozens of people have been killed, while thousands have fled.

Moscow launched the offensive in the early hours of the morning, shortly after President Vladimir Putin declared war in a dramatic televised address. He threatened any country attempting to interfere with "consequences you have never seen".

Air and missile strikes rained down on cities and military bases, before tanks rolled in across three sides of Ukraine's vast border. It followed weeks of escalating tensions, as Russia massed troops around the country.

Ukraine's President Volodymyr Zelensky, meanwhile, vowed to continue fighting. He said "a new iron curtain" was falling into place and his job was to make sure his country remained on its western side.

Mr Zelensky ordered conscripts and reservists in all of Ukraine's regions to be called up to fight. The country's defence minister urged anyone who was able to hold a weapon to join the effort to repel Russia.

But as night fell, fears of a Russian assault on the capital grew. Gunfire and explosions were heard in the city throughout the day and the president was quoted in Ukrainian media as saying "saboteurs" had entered Kyiv.

Western intelligence officials earlier warned that Russia was building an "overwhelming force" to take control of the city.