Russia's defence ministry said on Thursday it had taken out military infrastructure at Ukraine's air bases and "suppressed" its air defences, Russian news agencies reported.
The ministry denied reports that its aircraft had been downed over Ukraine.
Earlier, Ukraine's military had said five Russian planes and one helicopter were shot down over its Luhansk region.
"The air defence assets of the Ukrainian armed forces have been suppressed," Interfax news agency quoted the ministry as saying.
"The military infrastructure of the Ukrainian Armed Forces' air bases has been taken out of action.
"Information in foreign media about a Russian plane allegedly being shot down is not true."
Trump says Iran war deal close as Strait of Hormuz tensions linger
Two killed, 10 injured in Ukraine attack on Russia's border Bryansk region
Trump cancels US strikes on Iran, citing progress in talks
South Korea court sentences ex-President Yoon to 30-year jail term in drone case
Thai king's eldest daughter dies, aged 47, after long illness
US confirms third strike on Indian-crewed tankers this week
UK defence minister Healey quits, says PM Starmer's plans fail to keep country safe
False alarm at the Pentagon triggers brief shelter-in-place order
