MOSCOW, March 29 (Xinhua) -- Russian President Dmitry Medvedev said Monday that his country will fight terrorism without hesitation and to the end, local media reported.
Medvedev, who has ordered to beef up security on transport all over the country, said Russia will continue to fight terrorism.
"We will continue the operation against terrorists without hesitation and to the end," he told Russian media at an urgent meeting for the metro explosions.
"It is difficult to prevent such terrorist attacks and to provide security on transport," the president said. "It is necessary to tighten what we do, to look at the problem on a national scale, not only relating to a certain populated area but on a national scale. Obviously, what we have done before is not enough."
According to the latest official figure, the death toll of the blasts has reached 37, and the injured were 65.
Head of Russia's Federal Security Service (FSB) Alexander Bortnikov said the twin blasts were linked to groups related to North Caucasus.
He said the explosive device used in Lubyanka station was equivalent to 4 kg of TNT, while the Cultural Park station blast was equivalent to 1.5 to 2 kg of TNT.
A police source earlier told the RIA Novosti news agency that an inspection of the scene indicated that the bomb was detonated at a height of 100-200 centimeters, which would "apparently be attached to the waist of a female suicide bomber."
Closed circuit TV showed that 2 other women accompanied the suicide bombers onto the metro, reported Russia Today TV station.
Oleg Yelnikov, the spokesman of the Interior Ministry, said on TV that 700 interior troops were now patrolling the streets and massive police operation has been launched in Moscow.