Ukraine claims it has been attacked across Belarusian border

The military operation waged by Russia against Ukraine has came not only from across their shared border, but also from Belarus, the Ukrainian Border Guard Service has claimed.

According to its authorities, Ukraine was attacked at around 5am on Thursday morning across both frontiers, targeting the regions of Lugansk, Sumy, Kharkov, Chernihiv, and Zhytomyr.

Kiev has provided no direct evidence to support its assertion, but CNN has broadcast CCTV footage purportedly showing tanks crossing into Ukraine from Belarus. Russia has yet to comment on the allegation. 

In another video, the Border Service of Ukraine showed a column of Russian equipment passing through the border crossing in Crimea. Moscow has claimed that Ukrainian guards haven't offered any resistance to Russian units.

"Attacks on border units, border gear, and checkpoints are occurring with the use of artillery, heavy equipment, and firearms," the Border Guard Service wrote on Facebook.

The claim follows a statement by Ukrainian Foreign Minster Dmytro Kuleba that Russia had launched a "full-scale invasion."

"Peaceful Ukrainian cities are under strikes. This is a war of aggression," Kuleba wrote on Twitter. "Ukraine will defend itself and will win. The world can and must stop [Russian President Vladimir] Putin. The time to act is now."

The military operation came after Putin signed a decree authorizing the use of military force, following a request for support from the leaders of the Donetsk (DPR) and Lugansk (LPR) People's Republics. 

“Circumstances require us to take decisive and immediate action," the order read.

In a televised address to the nation, the Russian president said he wanted to "demilitarize" and "de-Nazify" Ukraine.