The Investigative Committee has finalized charges against 10 suspects in the Nevsky Express train blast that left 28 people dead and more than 90 injured in 2009, Interfax reported Thursday.
The suspects, identified as Zelimkhan Aushiyev and nine people with the surname Kartoyev, all close relatives, were detained in Ingushetia last spring during a law enforcement raid that killed seven militants, including warlord Said Buryatsky, the report said, citing the agency's spokesman, Vladimir Markin.
According to earlier reports, the suspects have pleaded not guilty.
Markin did not say whether the suspects have admitted involvement, but claimed that investigators had sufficient evidence to back the charges.
The investigation is to end in March, Markin added. It was unclear when the case might go to court.
The 2009 blast derailed the high-speed train traveling from Moscow to St. Petersburg. A similar attack was carried out in 2007 but resulted in no deaths. The Federal Security Service blamed the 2007 bombing on suspected Islamist militant Pavel Kosolapov, who remains at large.