Flags flew at half-mast on government buildings and at the Kremlin as a day of national mourning for the victims of the Moscow tube blasts began.
Police with machine guns patrolled underground station entrances amid tight security after yesterday’s suicide bombings.
The death toll from the attack rose to 39 today after a woman died in a Moscow clinic from her injuries.
Russia’s prime minister vowed to track down and kill the terrorists behind the atrocity which injured scores of people.
Health official Andrei Seltsovsky told the Rossiya-24 state news channel that five people out of 71 in hospital remained in a critical condition.
He said only eight of the victims had been formally identified.
The two women bombers targeted the city’s tube network during the rush hour, the first in Moscow in six years. One attack was at the station beneath the headquarters of the secret police.
Russian police have killed several Islamic militant leaders in the North Caucasus recently, including one last week in the Kabardino-Balkariya region, which raised fears of retaliatory strikes and escalating bloodshed by the militants.
As smoke billowed through the underground tunnels not far from the Kremlin and dazed survivors streamed out of the vast transportation system, al-Qaeda-affiliated websites were abuzz with celebration of the attacks by the bombers.
The bombings followed a warning last month from Chechen rebel leader Doku Umarov that “the war is coming to their cities”.
Prime minister Vladimir Putin, who built much of his political capital by directing a fierce war against Chechen separatists a decade ago, promised to hunt down and kill the organisers of what he called a “disgusting” crime.
“The terrorists will be destroyed,” he said on national television.
In a televised meeting with President Dmitry Medvedev, Federal Security Service head Alexander Bortnikov said the remains of the two bombers pointed to a Caucasus connection.
“We will continue the fight against terrorism unswervingly and to the end,” Mr Medvedev said.
Umarov, the Chechen rebel leader, has relied on al Qaeda’s financial support and has several al Qaeda emissaries in his entourage, says Alexander Ignatenko, the head of the independent Moscow-based Institute for Religion and Politics, who has closely followed the Islamic uprising in the Caucasus.
World leaders, including US president Barack Obama, UK prime minister Gordon Brown and, condemned the attacks. Mr Obama telephoned Mr Medvedev to convey the condolences of the US.
AP