Radiation at the Chernobyl nuclear power plant has exceeded control levels after Russia troops took control of the area, Ukraine has said.

Data from the automated radiation monitoring system of the exclusion zone, which is available online, indicate that the control levels of gamma radiation dose rate, which show up as red dots, have been exceeded at a significant number of observation points, its parliament said in a statement.

The statement added that it is "currently impossible to establish the reasons for the change in the radiation background in the exclusion zone because of the occupation and military fight in this territory."

Russia's defence ministry claimed that the radiation levels coming out of the power plant are normal.

Moscow said it would send paratroopers to the area to help secure it, the Russian defence ministry added in a statement.

A spokesman claimed that Russian troops have destroyed 118 Ukrainian military infrastructure sites.

Fighting continued in cities across Ukraine on Friday morning during day two of Russia's invasion of its neighbour.

Missiles pounded the Ukrainian capital Kyiv in early morning raids as Russian forces pressed their advance.

Volodymyr Zelenskiy, the Ukrainian President pleaded with the international community to do more, saying sanctions announced so far were not enough.

Air raid sirens wailed over the city of 3 million people, where some were sheltering in underground metro stations, a day after Vladimir Putin, the Russian president launched an invasion that has rocked the world.

A Ukrainian official said a Russian plane had been shot down and crashed into a building.