“According to preliminary information, these acts were committed by terror groups linked to North Caucasus,” stated Aleksandr Bortnikov, the director of the Federal Security Service. “We will consider this the main version of events as the bodies of two female suicide bombers who were residing in the North Caucasus were found at the sites.”

Umarov, 46, is thought to be one of those who organized the Beslan school siege in 2004, which ended in a blood bath.

Along with the investigation in Moscow, another has begun in the South of Russia. Chechen President Ramzan Kadyrov says he is ready to give all assistance possible to the investigators.

“We are ready to cooperate,” said Ramzan Kadyrov, the president of Chechen Republic. “We have the experience, we have the law enforcement structures and special services – they know all the ins and outs. We all witnessed what these people did in the Chechen Republic: they are trying to scare ordinary people and undermine the rapidly expanding economy, locally and throughout the country.”

The latest attack is widely believed to be in retaliation to successful police and security operations in Russia’s North Caucasus.

The bombings come less than a month after ten alleged militants were arrested in the North Caucasus region. They are accused in connection with the bombing of the Moscow to St. Petersburg express train last November, which killed more than two dozen people.

In addition, last month three militant leaders in the North Caucasus were killed in a shootout with security services, one of whom was thought to have trained suicide bombers.