An explosive device used in the killing of a Russian colonel in St. Petersburg was reportedly transported into the Leningrad Region from the Baltic states using a hot-air balloon.

The report said an unidentified person retrieved the explosives and placed them in a hidden cache. The device was later collected by a 31-year-old man from St. Petersburg who was born in the Pskov Region, according to ASTRA.

The suspect subsequently monitored the colonel for at least a month after taking a job as a delivery worker at a Lenta hypermarket.

At around 1:00 a.m. (GMT+3), he attached an explosive device underneath a vehicle parked near the supermarket on Kolpinskoye Highway.

The man reportedly boarded a flight to Istanbul at 2:43 a.m. and landed at 6:05 a.m. By the time the explosion occurred, he was travelling towards Chisinau, Moldova.

The deceased had two children.

These details appear to match Colonel Dmitry Lobodin, chief navigator of the 6th Air and Air Defence Army, who reportedly has two adult sons, Rostislav and Kirill.

The latest explosion occurred just 600 metres from the site of a similar attack on a serviceman in August. In that incident, the serviceman's wife was also injured, and both victims reportedly lost their legs.

The August victim may have been Major Sergey Sechkov, who served in the 332nd Separate Guards Helicopter Regiment. Ukraine's Defence Intelligence had previously accused the regiment of carrying out missile and bomb strikes against civilians in Ukraine's Slobozhansky direction, including areas of Sumy and Kharkiv regions.