Ukraine unleashed more than a hundred drones smuggled deep into Russia in what it called its most damaging attack yet.

Ukraine’s strikes on distant Russian airbases with drones smuggled into the country are believed to have destroyed several of Moscow’s long-range bombers.

A Ukrainian drone attack has destroyed more than 40 Russian planes deep in Russia’s territory, Ukraine’s Security Service said on Sunday, while Moscow pounded Ukraine with missiles and drones just hours before a new round of direct peace talks in Istanbul.

Russia and Ukraine have shared blueprints for a peace deal that demonstrate how far apart the warring parties are.

Russia and Ukraine have agreed to swap 6,000 bodies of soldiers killed in action. The agreement emerged Monday at the latest peace talks in Turkey, where the two sides met for just over an hour, Ukrainian President Volodymyr Zelenskyy and Russian state media said.