Sirens rang out across Ukraine's capital city of Kyiv on Friday morning.
CNN witnessed a group of Ukrainian security forces leave the city police headquarters with weapons and ammunition -- apparently heading towards the northern district of Obolon, where fighting has been reported.
What is happening in Kyiv? Ukrainians in the capital huddled in air raid shelters Friday morning, amid claims of troops blowing up a bridge to stop an advance of Russian forces.
The Ukrainian Defense Ministry said Russian reconnaissance troops have entered Obolon, which is just a few miles from the city center.
The ministry in a tweet asked citizens of the district to report any suspicious movements and adds: "Make Molotov cocktails and take down the occupier."
Before dawn, explosions lit up the sky as Russia targeted the city with missile strikes, according to a Ukrainian government adviser. A CNN team reported hearing two large blasts in central Kyiv and a third loud explosion in the distance, followed by at least three more explosions to the southwest of the city a few hours later.
The Ukrainian Defense Ministry said airborne assault troops blew up a bridge over the Teteriv River at Ivankiv, about 30 miles (50 kilometers) north of Kyiv, successfully preventing a Russian column of forces from advancing towards the capital.
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