The Nevsky Express hurtled off the rails near Veliky Novgorod August 13 on the country's busiest rail line linking Moscow and St. Petersburg following an explosion that left a crater in the tracks. Carriages were overturned and dozens were injured.
"We are considering the three likeliest versions: a Chechen "connection," a criminal act related to the replacement of the Novgorod Region governor and a terrorist act by nationalist youth groups from Moscow or St. Petersburg, the most serious version," said Alexander Bastrykin, head of the investigating committee at the General Prosecutor's Office.
He said there was enough evidence to track down the criminals and solve the case.
On August 19, law enforcement officials detained a 23-year-old resident of the Novgorod Region suspected of involvement in the blast. Two days later, a local court ordered the arrest of Hasan Didigov, a migrant from the Chechen Republic in the North Caucasus, which has seen two wars in the 1990s-early 2000s.
Murad Yunusov, Didigov's lawyer, said official charges have not yet been filed against his client, which under Russian law must be done within 30 days following an arrest.
The lawyer said Didigov has pleaded not guilty.
