The son of a Sofia prosecutor has been behind the wheel of a BMW, which killed two people in the capital, while they were standing on the sidewalk.

"We're all in shock. My son was involved in the incident last night. I'm really sorry for what happened. This is the biggest nightmare for any parent. My son is an adult and will be held responsible," reads a statement by Sofia City prosecutor Ventsislav Andreev, circulated to the media.

The prosecutor points out that the investigation will decide what the punishment for his son Bisser will be and delivers his condolences to the relatives of the two killed persons – a man and a woman in their thirties.

More than twenty hours after the tragic incident no one has been arrested as police is waiting for the technical expertise to be ready.

The incident happened a little bit after 1 am when an Audi with Sofia registration, driven by a 23-year-old man, traveling on Bulgaria Boulevard, hit sidewise a BMW, also with Sofia license plates, driven by a 21-year-old man.

The impact sent the automobiles on the sidewalk where a man, 39, and a woman, 34, have been standing near a public transportation bus stop. The two died in the hospital shortly after the incident.

There are suspicions that the two drivers were part of the fairly new game, known as "Russian road roulette", which is played every night at intersections throughout the Bulgarian capital.

The craze took hold in the summer two years ago and according to the rules, participants, most of them in their twenties and driving sports utility vehicles, must drive at top speed and not apply their brakes.

Onlookers also take part by gambling on the outcome.