MOSCOW - Russian authorities have detained an Uzbek citizen in connection with the deaths of a senior military official and his assistant, the Russian Investigative Committee said on Wednesday.

The 29-year-old suspect, accused of carrying out a terrorist attack that resulted in the deaths of Lieutenant General Igor Kirillov, head of the Russian armed forces' radiological, chemical and biological defense troops, and his assistant, has been detained.

According to the committee, the suspect was recruited by Ukrainian intelligence services and given a homemade explosive device after he arrived in Moscow. He allegedly placed the device on an electric scooter parked near the entrance of the building where Kirillov resided.

The suspect is said to have rented a car to monitor the general's residence, installing a camera that transmitted live footage to the attack's organizers in Dnipro, Ukraine. Once the two officials left the building, the suspect remotely detonated the explosive device.

In exchange for carrying out the attack, the detainee was promised a reward of 100,000 US dollars and relocation to a European country, the committee said.

Kirillov and his assistant were killed on Tuesday when the explosive device, concealed on the scooter, detonated outside the residential building.