An unidentified individual detonated an explosive device near a railway station in Moscow early Tuesday morning, killing himself and a police officer. Two other people were injured in the explosion.

Early reports said the attack occurred a few minutes after midnight near the Savyolovsky rail station, a major hub for passenger transportation in downtown Moscow. The attacker approached a police vehicle and detonated his device in an apparent suicide bombing.

The police car was heavily damaged, appearing in local media reports with shattered windows, but it did not catch on fire.

The Russian Investigative Committee later said the suspect was a 22-year-old male from the republic of Udmurt in western Russia.

“As a result of actions by the attacker, one traffic policeman sustained injuries incompatible with life and died at the scene of the incident. Two more policemen were taken to a city hospital, where they are being given medical assistance,” the Investigative Committee said.

On Tuesday afternoon, the Russian Interior Ministry identified the slain police officer as Lt. Denis Bratuschentko, 34, a senior inspector who joined the traffic police force in 2019. The ministry said he was survived by a wife and two children.

“The leadership and personnel of the Ministry of Internal Affairs of Russia express their sincere condolences to the family,” the ministry said.

The Republic of Udmurt is heavily, but not exclusively, populated with its own ethnic group, who have their own distinct language but mostly speak Russian. The name of the Udmurts loosely translates to “meadow people,” but in the modern era their region has become heavily industrialized.

Udmurtiya, as the region is sometimes known, is not terribly restless or prone to violent disruptions, although some Udmurts have expressed concern at becoming a minority in their own traditional homeland. The region is currently dominated politically by the ruling United Russia party. Some Russian media reports on Tuesday speculated that the bomber might have been passing through Udmurtiya, rather than having been born there.

The Udmurt Republic was the target of a major Ukrainian drone strike on Saturday, specifically a Russian state-owned defense enterprise called the Votkinsk Machine Building Plant. The factory is noted for producing Iskander ballistic missiles, which Russia has used extensively against Ukraine.

At a meeting of Russia’s FSB security service on Tuesday, President Vladimir Putin suggested the Moscow bomber could have been an “unwitting accomplice” recruited online by Ukrainian intelligence.

Putin accused the Ukrainians of “doing everything they can to pull off some kind of provocation” in order to derail peace talks brokered by the United States. He said a surge in terrorist attacks last year was “undoubtedly” carried out by Ukrainian operatives.

Putin ordered the FSB to increase protection for government officials who could be targeted by Ukraine.

“Together with other law enforcement agencies, the FSB needs to increase the protection level for Defense Ministry officials, the defense industry, state and municipal authorities, as well as education and social workers,” he said.