Ukrainian forces downed an enemy aircraft over Kyiv early Friday morning, which then crashed into a residential building and set it on fire, said Anton Herashchenko, an adviser to the interior minister, according to Reuters.

It was unclear whether the aircraft was manned. Herashchenko wrote on Telegram that a nine-story residential building was on fire. He did not specify how many people, if any, were in the building at the time of the incident.

He added that a series of explosions heard earlier in Kyiv the sounds of the Ukrainian air defenses firing at the aircraft.

In another incident early Friday morning, missiles hit a military post in southeastern Ukraine, near the city of Zaporizhzhia. A Ukrainian official said that several soldiers were killed and wounded.

Meanwhile, US officials estimated that Russian mechanized forces that had entered Ukraine through Belarus were about 32 kilometers from Kyiv.

Earlier, Ukraine’s President Volodymyr Zelensky signed a decree ordering a general mobilization following the Russian invasion of his country.

Conscripts and reservists in all of Ukraine’s regions will be called up, according to the decree published by the Ukrainian presidency, which is to be in effect for 90 days.

Zelensky also said that 137 Ukrainians died in the first day of the large-scale attack from Russian forces.

"Russian sabotage groups infiltrated Kyiv. According to the information we have, the enemy marked me as target number 1, and my family as target number 2. I remain in the government district. Ukraine has been left alone to fight Russia," the Ukrainian President further said.