An attacker detonates an explosive device in Moscow, killing a police officer and himself

MOSCOW (AP) — An unidentified assailant detonated an explosive device next to a patrol vehicle in Moscow early Tuesday, killing himself and a police officer, and leaving two other officers injured, officials said.

The attack happened minutes after midnight near the Savyolovsky Train Station in the Russian capital’s downtown, according to Moscow’s branch of the Interior Ministry.

It said the assailant approached a traffic police vehicle and detonated an explosive device, killing an officer on the spot and injuring two others, who were hospitalized.

Russia’s Investigative Committee said it has launched a probe into the attack. It didn’t name the assailant or give any information about his possible motives or any further details.

The attack came on the day marking the fourth anniversary of Russian President Vladimir Putin’s decision to send troops into Ukraine.