MOSCOW, April 12 (RIA Novosti) - Four people were killed and two injured in a traffic accident on a side road in the Moscow Region's southwest Saturday, a traffic police spokesman said.

"Under unclarified circumstances, a Mercedes car whipped into the oncoming lane and collided head-on with a Zhuguli VAZ-2107. The Zhiguli's driver and three passengers, including a 9-year-old child, died. The Mercedes' driver and passenger were injured and hospitalized," the spokesman said.

An investigation is underway.