A senior Russian military officer was killed when a car exploded on Friday in the town of Balashikha just east of Moscow, Russia's Investigative Committee said.
It named the officer as Yaroslav Moskalik, deputy head of the Main Operations Directorate of the General Staff of the Russian Armed Forces, and said it had opened a criminal case into the incident.
"According to available data, the explosion occurred as a result of the detonation of a homemade explosive device filled with destructive elements," the Investigative Committee said in a statement.
The statement did not say who might be behind the incident. Several high-ranking Russian military figures have been assassinated since the start of the war in Ukraine in operations blamed by Moscow on Kyiv.
Russian media outlet Baza, which has sources in Russia's law enforcement agencies, said a bomb in a parked car had been detonated remotely when the officer - who lived locally - walked past.
Who was Moskalik?
The Izvestia newspaper published video footage showing a person approaching a line of parked cars outside an apartment complex and an explosion that sent parts of a vehicle flying meters into the air.
Kommersant newspaper said a second person was also killed.
Moskalik, who held the rank of major general, had participated in several high-level Russian delegations, according to defense ministry bulletins and media reports.
He joined the Russian contingent in a meeting in October 2015 of the Normandy Format, a group made up of teams from Germany, Russia, Ukraine, and France who oversaw the Minsk agreements designed to end the war between Ukraine and Russian-backed separatist forces that broke out in 2014.
Moskalik represented the army's General Staff at the negotiations alongside Foreign Minister Sergei Lavrov and Kremlin aide Yuri Ushakov, according to the Kremlin website.
Russia's RBC newspaper listed Moskalik as a participant in the security subgroup in the Minsk talks.
In December, Ukraine's SBU intelligence service used a bomb hidden in an electric scooter to kill Lieutenant General Igor Kirillov, whom Kyiv accused of being responsible for the use of chemical weapons against Ukrainian troops.
The SBU did not immediately respond to a request for comment on the reported death of Moskalik.