Black smoke rises from a military airport in Chuhuiv near Kharkiv on Thursday. Explosions were heard across the country soon after Russian President Vladimir Putin announced his military would begin operations in its neighbor. Photo: VCG

A convoy of Russian military vehicles moves toward the border in the Donbas region of eastern Ukraine on Wednesday from the Russian border city of Rostov. Photo: VCG

Residents of Kyiv leave the Ukrainian capital Thursday morning as Russia’s military began operations in the country. Photo: VCG

Putin (left) announced the order Thursday in a televised speech in Moscow. Meanwhile, Ukrainian Foreign Minister Dmytro Kuleba tweeted that “Putin has just launched a full-scale invasion of Ukraine.” Photo: IC Photo

The United Nations held an emergency Security Council meeting on the Ukraine crisis Monday after Russia recognized the independence of two separatist regions in its neighbor and ordered its military to act as peacekeepers. Photo: VCG

People evacuated from Donbas arrive at a railway station in Russia on Tuesday. Leaders of the Donetsk and Lugansk regions announced civilians were being evacuated to Russia as tensions escalated in eastern Ukraine on Friday. Photo: VCG

An instructor trains a woman to fire a rifle on Feb. 6 at a shooting range near Kharkiv, Ukraine’s second-largest city. Hundreds of civilians have undergone military training as tensions escalated. Photo: VCG

On Feb. 3, U.S. troops bound for Europe depart from Fort Bragg, North Carolina, amid fears Russia could invade Ukraine. Photo: VCG

Putin sits in a video meeting with U.S. President Joe Biden to discuss Ukraine in Sochi, Russia, on Dec. 7. Russia reiterated that military operations were still on the table in January after negotiations failed with the U.S., NATO, and the Organization for Security and Co-operation in Europe. Photo: VCG

Ukrainian soldiers walk the line of separation between Ukrainian and pro-Russian separatist forces near Katerynivka in eastern Ukraine on Dec. 7. The same day, Ukrainian authorities accused Russia of planning an invasion. Photo: VCG

A Ukrainian soldier fires at a drone from the frontline in the Donetsk region on Sept. 17. Photo: VCG

A Ukrainian soldier stands on top of an armored personnel carrier in a trench near the frontline in February 2015. Photo: VCG

Leaders from Russia, Ukraine, France and Germany prepare for a meeting in Berlin in February 2015 to discuss ways of implementing the ceasefire called for in the Minsk agreement. Photo: VCG

Masked pro-Russian soldiers guard a checkpoint in May 2014. Photo: VCG

A pro-Russian protester guards a barricade outside the regional state administration building in the eastern Ukrainian city of Donetsk in April 2014. Photo: VCG