A senior Russian military commander was killed on Friday in a car explosion in a suburb of Moscow, investigators said.

The Investigative Committee of Russia, the country’s equivalent to the F.B.I., issued a statement identifying the officer as Lt. Gen. Yaroslav Moskalik, a senior figure in the Russian General Staff who was directly involved in planning operations. The investigators said that they had opened a criminal inquiry into the explosion, which took place in the town of Balashikha, east of Moscow.

The explosion came as Russian state news agencies reported that Steve Witkoff, President Trump’s special envoy, was probably in Moscow. Mr. Witkoff was expected to conduct another round of high-profile negotiations with President Vladimir V. Putin over ending the war in Ukraine and re-establishing the bilateral relationship between Russia and the United States. Mr. Putin has cast aside Mr. Trump’s calls for a quick peace in Ukraine, and Russia’s airstrikes on civilian targets appear to be increasing.

General Moskalik’s death is the latest in a series of fatalities among Kyiv’s opponents inside Russia. The Ukrainian authorities had no immediate comment when contacted about the killing.

In February, a prominent pro-Russia separatist figure from Ukraine, Armen Sarkisyan, was killed when a bomb exploded inside a gated residence in Moscow. Ukrainian officials did not comment on the blast at the time.

At the end of December, a general in charge of the Russian military’s nuclear and chemical weapons protection forces, Igor Kirillov, was killed by a bomb near the entry to a residential building in Moscow. An official with Ukraine’s security service, known as the S.B.U., said at the time that Ukraine was responsible for the killing.