Video Producer: Shohini Bose
Video Editor: Deepthi Ramdas
President of Russia Vladimir Putin announced on 24 February that the Russian military will carry out a "special military operation" in Ukraine.
The operation will "protect" Russian people in eastern Ukraine, he claimed, after separatists in Donbas reportedly asked the Russian government for help.
Just after the announcement, explosions were heard across the country.
His address to the Russian people coincided with the United Nations Security Council meeting.
Putin said that a conflict between Ukrainian and Russian forces was "inevitable".
He reiterated that NATO's eastwards expansion was unacceptable, and Ukraine must not join the alliance.
Calling on Ukrainian soldiers to put down their weapons, Putin said he aims to "demilitarise and de-Nazify", Reuters reported.
He also said that any responsibility for violence and death will lie with Ukraine.
He also warned foreign powers to stay away. If they interfere, "Russia will act immediately", he warned.
President Zelenskyy, in his address to the nation said that he had spoken to US president Joe Biden, and told his fellow citizens to stay home and to stay calm.
"The army works. I will be with you all the time. Stay strong. We will win because we are Ukraine. Glory to Ukraine."
Ukrainian foreign minister Dmytro Kuleba tweeted confirmation about Russia’s "full-scale invasion" of the country.
"Putin has just launched a full-scale invasion of Ukraine. Peaceful Ukrainian cities are under strikes. This is a war of aggression. Ukraine will defend itself and will win. The world can and must stop Putin. The time to act is now," he wrote.
Ukraine's deputy interior minister, Anton Gerashchenko posted a statement regarding the attack on his Facebook page.
"The invasion has begun. There have just been missiles on the military headquarters, airports, military warehouses, near Kyiv, Kharkiv, Dnieper. Gunfire at the border is underway. From this day, there is a new geopolitical reality in the world," it read.
You can follow our coverage of the Russia-Ukraine crisis here.
(With inputs from Reuters and The Guardian)