Ukraine security service sources tell BBC bombers "are burning en masse" - as Russia confirms Kyiv's drone attack.

With 41 military aircraft impacted, the Ukrainian drone attack was described by some commentators as Russia's "Pearl Harbor." The attack on Pearl Harbor in December 1941 was a surprise air raid by Japan on the U.S. during World War II. Kyiv's assault follows ground advances by Moscow troops in recent days in Ukraine's Sumy border region.

By making harsh, uncompromising demands in peace talks with Ukraine while continuing to pummel it with waves of missiles and drones, Russian President Vladimir Putin is sending a clear message: He will only accept a settlement on his terms and will keep fighting until they’re met.

Ukraine launched a large-scale drone assault on multiple Russian air bases Sunday (June 1), reportedly striking more than 40 military aircraft. Separately, the Ukrainian Air Force on Sunday said that

With Russia saying its terms for peace must remain secret until the talks begin, Ukraine won’t confirm whether its delegation will even attend.

Two bridges have collapsed in Russia’s western regions bordering Ukraine, killing multiple people and injuring dozens, authorities said.

Two bridges have collapsed, causing trains to derail, in separate incidents within Russia, which Vladimir Putin's officials have blamed on "interference", a likely reference to Ukrainian saboteurs.At least seven people were killed and 30 suffered injuries after a bridge collapsed and a train derailed in Russia's Bryansk region that borders Ukraine,