by Yana Dlugy
MOSCOW, Aug 31 (AFP) - At least seven people were killed and 20 others injured after an explosion Tuesday outside a Moscow subway station that the Russian security service blamed on a female suicide bomber.
The explosion caused carnage outside the station and came just a week after 90 were killed in twin plane crashes over Russia that officials blamed on Chechen terrorists.
An interior ministry official said one version was that an explosive substance went off under the car parked outside the metro station, but the security service appeared only to be looking at the theory of a female suicide bomber.
"With a great deal of probability it can be said we are talking about a premeditated explosion carried out by a terrorist female sucide bomber," an interior ministry official told journalists.
Moscow prosecutor Anatoly Zuyev said that seven people had died in the blast and 20 were injured. He said prosecutors opened a investigation for terrorism. News agencies said as many as eight could have been killed.
The attacks frightened people in Moscow already on edge over possible attacks from separatists in Chechnya, who have vowed resistance in a war that has dragged on for five years.
"I was walking out of a nearby store when the blast went off and the first thing I saw were torn up bodies," said Alexei Borodin, 29.
"Some people were trying to stand up -- but they were no longer people," he said. "There were people without parts of of their bodies." He saw one person without a stomach as it had all fallen out.
"My mother told me -- `We are walking on human remains,`" he said.
Men in security service jackets walked through the scene as dozens of ambulances and fire trucks cut off traffic in northern Moscow.
The blast went off between a bustling Moscow subway station and a crowded supermarket. Smoke rose over sections of the Russian capital for several hours over the blast, whose shock waves smashed windows in the station.
News agencies said that the station was closed after the blast and would only reopen when the damage left by the blast was cleared up. Trains were going through the station without stopping.
Passengers were being told through loudspeakers to use different means of transportation or go to other stations.
Moscow mayor Yuri Luzhkov rushed to the scene and was expected to speak to reporters later Tuesday.
Police said that steps had been taken to increase security in the Russian capital with extra patrols of police dispatched to stations and airports.
Russian newspapers have said that female suicide bombers could have been behind the plane crashes on August 24, although this has yet to be confirmed by officials.