The Russian air force had one of its worst days of the war with Ukraine and lost four aircraft but it's not clear who shot them down. An Su-35, Su-34 and two Mi-8 helicopters were destroyed within minutes of one another in the same general area of Russian territory bordering northeastern Ukraine. They were apparently all on the same strike mission against Ukraine and the ability to carry out that kind of defensive strike would have been a stunning victory for Ukraine forces. But the Ukrainians claim they didn't do it.
This is a companion discussion topic for the original entry at https://www.avweb.com/aviation-news/four-russian-aircraft-downed-ukraine-denies-responsibility