Russian people are mourning around the subway stations, covering them with flowers and candles in memoir of the victims.
Speculations are rife that those behind the attack are of Caucasian origin but no one claimed responsibility so far.
Implying Al Qaeda indirectly, Foreign Minister Sergei Lavrov said the international community knew how strong the terrorist are near Afghanistan-Pakistan border, noting that those militants may organize attacks reaching up to Caucasian land, not only in Afghanistan.
Commentaries say the attack was a response to Russia's latest operations in Northern Caucasia, resulting in 20 militants' death.
Russian televisions banned amusement and magazine shows.
A nationwide mourning is declared in the country. President Medvedev and Prime Minister visited those rescued wounded from the attack.
Both leaders expressed resolve on finding and terminating the responsible.
US administration shared grief of Russia, noting terrorism is a common enemy and they will fully support Moscow administration for bringing the responsible before justice.
This has been the third terrorist attack since 2004 targeting Russian capital Moscow, which has quelled the uprisings in Chechnya by using disproportionate force from time to time.