Nearly 200,000 Russians being evacuated after massive Ukrainian attack

Nearly 200,000 people are being evacuated following one of the largest Ukrainian attacks on Russian territory, Russian officials said Wednesday.

The overnight strikes marked the biggest combined attack on Russia's air force infrastructure since the start of the full-scale war, with three Russian military airfields targeted, sources in the Security Service of Ukraine told ABC News.

Russian air defense forces destroyed 117 Ukrainian drones and four Tochka-U missiles over eight regions of Russia overnight, including in Kursk, Voronezh, Belgorod and Nizhny Novgorod, the Russian Ministry of Defense said in a statement.

Local authorities did not confirm the airfields were attacked.

A state of emergency has been declared in the Belgorod region due to "daily Ukrainian attacks," Belgorod Gov. Vyacheslav Gladkov said Wednesday morning.

Nearly 194,000 people are going to be evacuated from the Kursk and Belgorod regions due to the Ukrainian military offensive, according to Russian outlets.

The last time Russians fled en masse from fighting inside the country was during the decadelong Second Chechen War, which started in 1999, according to the independent Russian outlet Agentstvo.

The overnight assault comes more than a week into Ukraine's major incursion into Russia.

Ukraine's top commander said Wednesday that Ukraine has advanced again inside Russia's Kursk region as it continues to try to expand its unprecedented incursion there.

Ukrainian Gen. Oleksandr Syrskyi briefed President Volodymyr Zelenskyy that Ukrainian troops had advanced about 1 mile in different directions inside Kursk. Syrskyi also said Ukrainian forces had completed search-and-destroy operations for Russian forces still in Sudzha, the main border town from which Ukrainian forces have been expanding their bridgehead inside Russia, implying Ukraine now has full control over it.

Some Russian pro-Kremlin military blogger accounts in their latest reports gave similar pictures, suggesting Ukrainian forces had continued to consolidate their gains and were still pushing to expand their zone of control, though without any major advances.

"Unfortunately, for now the situation remains tough. The enemy for now still has the initiative and so, even if slowly, he is continuing to increase his presence in the Kursk region," one military blogger, Yury Podolyak, wrote on his Telegram channel.

The blogger account Rybar, which is linked to Russia's military, wrote the situation was "stabilizing" but nonetheless reported multiple efforts by Ukraine to break through Russian positions and intense fighting.

Ukraine continues to try to push in multiple directions from Sudzha. Ukrainian troops are still attempting to flank the village of Korenevo, which would allow them to move toward a key highway. Ukrainian troops are also reported to still be attempting to press north toward Lgov, a town closer to the Kursk nuclear power station, though for now they appear to remain at least 12 miles away.

Podolyak wrote that Ukraine has adapted its tactics, beginning to stop trying to make rapid advances with small columns of armored vehicles and instead was attempting larger, more consolidated assaults.

All indications are Ukraine is still on the attack in the Kursk region and Russian troops are battling hard to hold them back.

ABC News' Tanya Stukalova contributed to this report.