Ukraine has agreed to a Russian proposal for a further round of direct peace talks even as both countries carried out massive strikes on each other.
"On Monday, our delegation will be led by [Defence Minister] Rustem Umerov," Ukrainian President Volodymyr Zelenskiy wrote on the platform X, calling for talks at a high level to ensure lasting peace.
The meeting will take place in Istanbul.
Zelenskiy is calling for a complete and unconditional ceasefire, the release of prisoners and the return of abducted children.
The second round of talks, announced by Russian Foreign Minister Sergei Lavrov on Wednesday, will come a day after both sides carried out particularly stinging attacks.
Russia suffered an apparent co-ordinated attempt to disrupt railway lines as well as drone attacks on four military airfields, while Ukraine said Russia had hit a military training unit, killing 12, and damaged critical infrastructure in the city of Zaporizhzhya.
Zelenskiy called the surprise attack on Russian military airfields a "brilliant operation", saying it had been in preparation for more than a year and a half.
"Planning, organisation, every detail was perfectly executed. It can be said with confidence that this was an absolutely unique operation," Zelenskiy wrote on X.
At least seven people were killed and some 70 injured when two bridges collapsed in two Russian regions bordering Ukraine, local officials said.
Russian investigators said the overnight collapse of the two bridges near the border with Ukraine was caused by "acts of terrorism", according to the Interfax news agency.
In Bryansk, Governor Alexander Bogomaz confirmed reports of an explosion on a bridge, about 80km from the border with Ukraine. The train en route from Klimovo to Moscow had been carrying 388 people, Bogomaz said.
A section of the bridge collapsed and then fell onto a train passing underneath, state-run Russian news agency TASS reported.
In neighbouring Kursk, one person was injured when a freight train derailed after another bridge collapsed overnight, according to Alexander Khinshtein, the governor of the region.
Ukrainian intelligence has repeatedly carried out acts of sabotage and attacks on Russian territory as the country continues to fend of the full-scale invasion launched by Moscow on February 24, 2022.
While the Ukrainian military has not commented on the twin incidents, its intelligence service reported a train blast in occupied south-western Ukraine.
The military train en route to the Black Sea peninsula of Crimea carrying fuel tanks and freight cars derailed as a result of an explosion early on Saturday, the statement said.
The blast disrupted an important logistical route for the Russian military in the occupied areas of Zaporizhzhya and Crimea.
Elsewhere in Ukraine, at least 12 people were killed in a Russian missile strike on an army training unit, according to the military. More than 60 people were injured in Sunday's attack, according to a statement by the ground forces.
The commander of the Ukrainian army, General Mykhailo Drapatyi, took responsibility for the incident and announced his immediate resignation on Facebook.
The Ukrainian intelligence agency SBU meanwhile said it has attacked four Russian military airfields in a co-ordinated operation that destroyed more than 40 combat and reconnaissance aircraft.
An airfield in Siberian Irkutsk was also targeted, Russian media confirmed. However, Russian media did not provide any details about the destroyed aircraft.
The SBU said "Operation Spiderweb" led to the destruction of Tupolev Tu-95 and Tu-22 combat aircraft as well as Beriev A-50 early warning aircraft.
Ukrinform news agency quoted SBU sources as saying that its forces had hidden the combat drones under the roofs of wooden mobile homes that were transported on trucks.