MOSCOW -- Twin explosions rocked the capital of Dagestan on Monday, killing four people and injuring dozens in the Russian region most recently known for its association with the Boston Marathon bombing suspects.
A car bomb detonated in the center of Makhachkala, the Itar-Tass news agency reported. As police rushed to the scene, another, more powerful bomb detonated in their midst, said Rasul Temirbekov, head of the Dagestan Investigative Committee.
He said the force of the explosion was possibly equal to more than 100 pounds of TNT. Thirty-five of the 40 or so injured people were hospitalized.
Makhachkala is where the parents of the Boston bombing suspects live and where the older of the two brothers, Tamerlan Tsarnaev, spent six months last year. During that time, authorities believe, he may have met with the Islamic militants who have pursued a violent secessionist campaign in Dagestan in recent years.
No group immediately claimed responsibility for Monday's bombings, and authorities did not say if any group was suspected.
Also Monday, Russian authorities said they had killed two men and arrested a third in a preemptive operation against militants who were planning a major terrorist attack in central Moscow.
The National Anti-Terrorist Committee said it had carried out a raid in Orekhovo-Zuyevo, 40 miles east of Moscow.
“The criminals were Russian citizens who arrived from the area of Pakistan and Afghanistan, where they underwent combat training preparing them for a terrorist attack,” Dmitry Pavlov, spokesman for the committee, said in an interview to Rossiya 24, a state-run television news network.
Pavlov said police surrounded the three in a house in Orekhovo-Zuyevo. When they were given an opportunity to surrender, he said, "they opened fire.”
A special services officer sustained a light injury, Pavlov said.
One activist who has been critical of the Russian government's tactics in its battle against Islamic militants from the Caucasus region expressed skepticism about the official account of the raid.
“It is standard practice to kill somebody in the course of what they say was a special operation and then to declare the dead [as] terrorists without any evidence produced and a court ruling,” Alexander Cherkasov, chairman of Memorial, a human rights group based in Moscow, said in an interview with The Times. “In Chechnya and Dagestan these things happen every day when some young man is killed in what they say was a shootout, and the dead man is immediately declared a terrorist.”
However, Cherkasov acknowledged that Russia faces a problem of its citizens being recruited for militant training in Afghanistan and Pakistan.