"Yeah, I think it's relatively safe where I am," he replied as another huge blast went off, before pausing to put on a flak jacket and helmet.
It still remains unclear where the blasts came from, but they occurred just minutes after Russian leader Vladimir Putin announced a "military operation" in the region.
It came as Putin called on Ukraine's soldiers there to lay down their arms, defying Western outrage and global appeals not to launch a war.
Putin made a surprise statement on television to declare his intentions. "I have made the decision of a military operation," he said shortly before 6am local time in Moscow, as he vowed retaliation against anyone who interfered.
He also called on the Ukraine military to lay down its arms. His statement came after the Kremlin said rebel leaders in eastern Ukraine had asked Moscow for military help against Kyiv.
In response, Ukraine's President Volodymyr Zelensky made an emotional late-night appeal to Russians not to support a "major war in Europe".
Speaking Russian, Zelensky said that the people of Russia are being lied to about Ukraine and that the possibility of war also "depends on you".
"Who can stop (the war)? People. These people are among you, I am sure," he said.
Zelensky said he had tried to call Putin but there was "no answer, only silence", adding that Moscow now had around 200,000 soldiers near Ukraine's borders.
Earlier the separatist leaders of Donetsk and Lugansk sent separate letters to Putin, asking him to "help them repel Ukraine's aggression", Putin's spokesman Dmitry Peskov said.
The two letters were published by Russian state media and were both dated February 22.
Their appeals came after Putin recognised their independence and signed friendship treaties with them that include defence deals.
Tens of thousands of Russian troops are stationed near Ukraine's borders, and the West had said for days that an attack was imminent.
