By Vladimir Soldatkin, Tom Balmforth and Huseyin HayatseverISTANBUL (Reuters) - A massive Ukrainian drone attack on Russia's nuclear-capable strategic bombers overshadowed a new round of peace negotiations - the second such direct talks since 2022 - which got underway in Istanbul on Monday after an unexplained delay.

Ukrainian strikes on four Russian airbases mark an escalation in cross-border incursions before peace talks in Turkiye.

Ukraine's brazen attack on Russian airfields overnight sent a strong message ahead of peace talks. It also delivered a warning about the vulnerability of strategic assets against cheap and plentiful drones.

Ukraine has carried out large-scale drone strikes against four airbases deep inside Russia, destroying multiple combat planes, according to a source in the Ukrainian Security Service (SBU).

Russia has proposed another attempt at peace negotiations with Ukraine on Monday in Istanbul, but both sides remain firmly entrenched in positions likely to prolong the war.

We emphasize that no formations or mass gatherings of personnel were held,' says Land Forces of Ukraine's Armed Forces - Anadolu Ajansı

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

Ukraine's President Volodymyr Zelenskiy speaks to the media during a press conference, amid Russia's attack on Ukraine, in Kyiv, Ukraine May 13, 2025. REUTERS/Valentyn Og