Russian Foreign Minister Sergei Lavrov said militants operating on the Afghan-Pakistan border may have helped organize suicide bomb attacks that killed 38 in Moscow on Monday, Interfax news agency reported on Monday.
Two female suicide bombers attacked Moscow metro stations during the Monday morning rush hour. Both likely had links to the North Caucasus, the centre of an Islamist insurgency against Moscow, the head of Russia's FSB state security service said.
Some Russian officials have said that the insurgents in the North Caucasus, which includes Chechnya, Ingushetia and Dagestan, have ties to Al Qaida, though many analysts have disputed the link.
Lavrov did not mention Al Qaida, but said the bombers may have had links to militants on the Afghan-Pakistan border, where Al Qaida militants, and Afghan and Pakistan Taliban fighters are present.
Asked if there could have been any foreign involvement in Monday's attacks, Interfax quoted Lavrov as saying: "I do not exclude that."
"We all know that the Afghan-Pakistan border, in the so called no-man's land, the terrorist underground is very well entrenched," Lavrov was quoted as saying.
"We know that many people there actively plot attacks, not just in Afghanistan, but also in other countries. Sometimes the trails lead to the Caucasus," he said.
Earlier Monday, Prime Minister Benjamin Netanyahu extended Israel's condolences to Russian President Dmitry Medvedev and Russian Prime Minister Vladimir Putin on Monday after at least 39 people were killed and more than 100 were wounded in a twin terror bombing in Moscow.
"Please accept our condolences, on behalf of the government and the Israeli people, to the families of the victims, and wishes of recovery for the wounded," Netanyahu wrote, condemning the attack and explaining how Israel identifies with the Russians, "as a country that is itself a target for terror."
"We stand with you," he added, "united with the enlightened nations in the battle against the terror that threatens the entire human race."
Russian Emergency Ministry spokeswoman Svetlana Chumikova said 23 people were killed at the Lubyanka station in central Moscow, located underneath the building that houses the main offices of the Federal Security Service, or FSB, the KGB's main successor agency.
A second explosion hit the Park Kultury station about 45 minutes later. Chumikova said at least 12 were dead there.
"I heard a bang, turned my head and smoke was everywhere. People ran for the exits screaming," said 24-year-old Alexander Vakulov, who said he was on a train on the platform opposite the targeted train at Park Kultury.
Explosives equivalent to around 6 kilograms of TNT were used in the two attacks, the FSB later added, according to a report by the Russian news agency RIA Novosti.
FSB director Alexander Bortnikov said the bomb at the Lubyanka station exploded with a force of up to 4kg of TNT and the second, at Park Kultury, had between 1.5kg and 2 kg of TNT.
He added that in both cases the bombs were packed with metal nuts and bolts meant to increase the destructive nature of the blast.
Moscow Mayor Yuri Luzhkov said both explosions were believed to have been set off by female suicide bombers as the trains entered the stations. In the first case, officials said the explosion was on the train; there was no immediate information on the location of the second blast.
"The first data that the FSB has given us is that there were two female suicide bombers," Luzhkov told reporters at the Park Kultury site.
A police source told RIA Novosti that the Lubyanka bomb was detonated at a height of 100-200 cm and was apparently attached to the waist of a female bomber.
Putin vowed on Monday to detroy those responsible for attacks.
"A crime that is terrible in its consequences and heinous in its manner has been committed," Putin said at the start of a video conference with senior emergencies officials.
"I am confident that law enforcement bodies will spare no effort to track down and punish the criminals. Terrorists will be destroyed," said Putin, who was on a visit to the Siberian city of Krasnoyarsk.
United States President Barack Obama condemned the bombings in the Moscow metro, offering his condolences to the Russian people. In a statement issued by the White House early Monday, the president said:
"The American people stand united with the people of Russia in opposition to violent extremism and heinous terrorist attacks that demonstrate such disregard for human life, and we condemn these outrageous acts"
The last confirmed terrorist attack in Moscow was in August 2004, when a suicide bomber blew herself up outside a city subway station, killing 10 people.
Responsibility for that blast was claimed by Chechen rebels and suspicion in Monday's explosions is likely to focus on them and other separatist groups in the restive North Caucasus region.
The Moscow subway system is one of the world's busiest, carrying around 7 million passengers on an average workday, and is a key element in running the sprawling and traffic-choked city.
The blasts practically paralyzed movement in the city center as emergency vehicles sped to the stations. Helicopters hovered over the Park Kultury station area, which is near the renowned Gorky Park.
Passengers, many of them in tears, streamed out of the station, one man exclaiming over and over "This is how we live!"
At least a dozen ambulances were on the scene.
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