An explosion occurred outside a subway station in northeastern Moscow around 8:15 p.m. local time Aug. 31. At least one bomb was planted in a car parked in the square outside the Rizhskaya metro/train station, between the station entrance and the Krestovsky supermarket-department store complex nearby. The bomb, reportedly loaded with metal bolts and other scrap, exploded when many Moscow commuters were heading home or shopping. Preliminary reports indicate at least eight people were killed and 18 were injured — 12 of them severely. Moscow law enforcement sources say investigators believe it was a militant attack, but that possible organized crime links also are being investigated. According to an eyewitness report, a man drove up and asked bystanders to move out of the way so he could park. After parking, the man locked the car and left; the car, a Zhiguli sedan, exploded five minutes later. Russian federal security services and the Interior Ministry say a female suicide bomber inside the car was possibly behind the blast. Based on the location and timing of the explosion, the target seems to be ordinary commuters. The Rizhskaya station is close to the complex where many people stop on their way home from work. The station also is a key transit point: a Prospekt Mira highway overpass is right above the station and some distance across the highway is a suburban railway station; there also are bus stops and trolley stops at Rizhskaya. A Chechen militant group was responsible for a backpack-bomb explosion against a Moscow subway car Feb. 6 that killed 39 people and injured more than 100. Security fears in Russia are high after two passenger planes exploded Aug. 24, and there seems to be a resurgence of militant activity in Moscow. The cause of the plane crashes was determined to be an attack after traces of the explosive hexogen were found at both crash sites. Moscow police said although the Aug. 31 bomb type is still being identified, the blast was approximately equal to 300 grams to 400 grams of TNT and the bomb appears similar to an explosive device used at a Moscow bus stop Aug. 24 that injured five people. In an Aug. 31 press conference in Sochi, Russian President Vladimir Putin linked Chechen militants to al Qaeda.