Russia is demanding that Ukraine hand over all those who have been connected to terrorist acts committed in Russia, including the head of Ukraine's SBU Security Service, the Russian Foreign Ministry said on Sunday.
The SBU immediately dismissed the demand as "pointless".
In a statement, the Russian Foreign Ministry listed violent incidents that have occurred in Russia since the conflict broke out in February 2022, including bombings that killed the daughter of a prominent nationalist and blogger, and an incident in which a writer was seriously hurt.
The ministry said investigations of these incidents showed that "the traces of these crimes lead to Ukraine".
"Russia has turned over to Ukrainian authorities its demands… for the immediate arrest and extradition of all those connected to the terrorist acts in question," the statement said.
"Ukraine's violation of its obligations under anti-terrorist conventions will result in it being held to account in international legal terms.
"The Russian side demands that Kyiv immediately cease all support for terrorist activity, extradite guilty parties and compensate the victims for damages."
The statement also referred to the recent mass shooting at a concert hall in Moscow in which 144 people died.
Alexander Bastrykin, head of Russia's Investigative Committee, the country's most important criminal investigation body, was quoted by Russian news agencies as saying on Sunday that work was proceeding to determine who was behind the attack.
SBU head Vasyl Maliuk earlier acknowledged that his agency was behind attacks on the bridge linking Crimea to the Russian mainland since Russia's special military operation in Ukraine began.
Maliuk last week dismissed Moscow's calls to arrest him, after giving a television interview detailing extra-judicial killings of Ukraine's opponents in Russia.
Stepping up campaign
On the front line, the Russian Defense Ministry said its air force has conducted a massive strike on objects of energy infrastructure and the gas industry inside Ukraine.
For over a week, Russia has stepped up an airstrike campaign against Ukrainian energy facilities, leaving many fearing a return to blackouts seen during the first winter of the full-scale conflict.
Ukraine's largest private energy firm DTEK said on Saturday that five of its six plants had been damaged or destroyed with 80 percent of its generating capacity lost, and that repairs could take up to 18 months.
Ukrainian energy company Centrenergo also announced that the Zmiiv Thermal Power Plant, one of the largest in the northeastern Kharkiv region, was completely destroyed following Russian shelling last week. Power outage schedules were still in place for about 120,000 people in the region, where 700,000 had lost electricity after the plant was hit on March 22.
In a message on Sunday to mark the date when some of Ukraine's Christians celebrate Easter, Ukrainian President Volodymyr Zelensky urged the country to persevere.
Meanwhile in Russia, 10 Czech-made Vampire rockets landed in the Belgorod region on Sunday, the Ministry of Defense said.
One woman was injured when a fire broke out following the attack, Belgorod Governor Vyacheslav Gladkov said. Another woman was killed as shelling hit villages along the Russian border.
