Russia has blamed Ukraine for a car bomb that killed a senior Russian military officer near Moscow on Friday, hours before United States President Donald Trump's envoy Steve Witkoff was due to meet President Vladimir Putin in Moscow.
There was no official comment from Ukraine on the death of 59-year-old Yaroslav Moskalik, the latest in a series of Russian military officers and pro-war figures to be assassinated since the start of Russia's war in Ukraine.
Witkoff met Putin to discuss US proposals for ending the war, now well into its fourth year.
Kremlin spokesperson Dmitry Peskov told a state TV reporter the "Kyiv regime" continued to be involved in "terrorist activity" on Russian territory.
"Despite the peace talks, we must be on guard," he said.

Police and investigators work at the scene where Yaroslav Moskalik was killed by an explosive device placed in his car. Source: AP / AP
That position would have given him an important role in planning Russian military operations, including in Ukraine.
State media said he held the rank of lieutenant general.
The body of a man, partially covered in a white sheet, lay on the pavement outside the entrance to an apartment building in the town of Balashikha, east of Moscow, near a burnt-out car.
"The explosion occurred as a result of the detonation of a homemade explosive device filled with destructive elements," investigators said in a statement.
Trump's Ukraine envoy, General Keith Kellogg, said that attack violated the rules of warfare.
Who was Yaroslav Moskalik?
Russian war bloggers described Moskalik as a rising star.
He had participated in several high-level Russian delegations that have met Western officials to try to negotiate a settlement to the conflict in Ukraine.
He also dealt with Syria, presenting a report on military-technical cooperation in Africa and the Middle East at a security forum in Moscow in 2021.
Rybar, a Russian war blogger with over 1.2 million subscribers on Telegram, said he was viewed as "one of the most intelligent and demanding officers" in his directorate.
The blogger said Moskalik was being considered to serve as head of the National Defence Management Centre, the supreme command and control centre of the Russian Armed Forces, due to his "systematic approach and thoughtfulness."