MAKHACHKALA, Russia — Six blocks from the Caspian Sea, on Kotrova Street in central Makhachkala, sits a mosque being watched by undercover Russian agents charged with preventing acts of terror.
As worshipers spill out into the streets, American investigators are watching now, too, as they try to reconstruct the events that led to the most high-profile terrorist assault in the U.S. since Sept. 11, 2001.
It’s here that Tamerlan Tsarnaev, the man U.S. authorities say masterminded the Boston Marathon bombings, went to worship during a six-month trip to Russia’s Dagestan region last year, according to his father. Since President Vladimir Putin tamed Tsarnaev’s ancestral homeland Chechnya, where federal forces fought two wars against Islamic militants, neighboring Dagestan has emerged as the center of separatist violence on the Russian side of the Caucasus Mountains.
“We know there were militants who started their path to Islam at this mosque,” Rezvan Kurbanov, a former deputy premier of Dagestan who oversaw security in the region in 2010 and 2011, said in an interview in Moscow. “We’ve had our eye on this mosque for a long time.”
Hundreds of mainly young men took to the street for afternoon prayers last Friday, halting traffic around the mosque because they were unable to squeeze into a building designed to hold 1,800. They knelt on sheets of cardboard, carpets and plastic bags and prayed along the dusty road.
About 3,000 thousand people attend Friday prayers at the mosque on average, said Ziyavudin Uyvasov, a representative of the community and a lawyer whose clients include men suspected of religious extremism.
“All kinds of people come here from many countries, but we don’t ask for passports,” Uyvasov said in an interview in Makhachkala, about 210 miles up the Caspian coast from Azerbaijan’s capital, Baku. “Some people express quite radical views and keep asking others what they think about jihad. They are provocateurs. We don’t talk to them.”
FBI agents are trying to uncover any link Tsarnaev may have had with extremist groups, Rep. Mike Rogers, R-Mich., chairman of the House Intelligence Committee, said on ABC News’s “This Week” on April 28. Investigators have persons of interest in Russia, he said.
Dagestan, which is almost twice the size of Massachusetts and less than half as populous, is the most violent region in Russia, with 53 bombings last year, according to the Caucasian Knot, a Moscow-based research group. There were also 405 violent deaths, including 110 troops and 231 extremists.
The Kotrova mosque adheres to the Salafist branch of Sunni Islam and its community is opposed to the Sufis who are backed by the Putin-appointed government, according to Uyvasov, the lawyer.
Several Muslim leaders loyal to authorities have been murdered in Dagestan in recent years, including Said Afandi al-Chirkawi, a 74-year-old Sufi scholar with 100,000 followers who was killed by a suicide bomber at his home last August, according the Interior Ministry.
The attacker was an ethnic Russian woman who gave up an acting and dancing career to convert to Islam before marrying an insurgent, the local Investigative Committee said at the time. She lived at Kotrova 124, down the street from the mosque, according the Interior Ministry.
Tsarnaev’s father, Anzor, said there was nothing sinister about the visits he and Tamerlan, 26, made to the mosque.
“If it’s seen as a radical place, it should be fully monitored, who goes there, whom they speak with,” the elder Tsarnaev told reporters in Makhachkala last week.
Tsarnaev started getting “serious” about Islam three years ago and spent most of his time in the Dagestani capital reading the Koran, according to Patimat Suleimanova, one of his aunts. A YouTube page in his name included videos by radical Australian cleric Feiz Mohammad.
One extremist Tsarnaev may have had contact with was William Plotnikov, a Russian-born Canadian who was killed during a raid on a rebel stronghold in the forests of Dagestan last year, according to Magomed Baachilov, head of the region’s Security Council. Both men were boxers and Plotnikov was from Toronto, where another of Tsarnaev’s aunts lives.
Foreign fighters often make their way to Dagestan, Baachilov said by phone April 29. “We kill many people from North Africa and the Middle East.”
Plotnikov was questioned by Russian officials about his Islamic beliefs in 2010 and identified Tsarnaev as a fellow member of an Islamic youth network, Novaya Gazeta reported April 27, citing an unidentified official in the Dagestani Interior Ministry’s Center for Combating Extremism.
Tsarnaev left Dagestan to return to the U.S. on July 16, two days after Plotnikov was killed, according to the Moscow- based newspaper, which is partly owned by former Soviet leader Mikhail Gorbachev.
He had been under surveillance by Russian operatives since the previous April, after making contact with a Dagestani- Palestinian jihadist recruiter named Nidal Mahmoud Mansour, Novaya Gazeta said. Mansour was killed by Russian forces in a raid on a home in Makhachkala in May, according to the Interior Ministry.
Tsarnaev died and his brother Dzhokhar, 19, was wounded in a shootout with police four days after the Boston attack, which killed three people and injured more than 260. The younger Tsarnaev is being held at a federal facility, charged with using and conspiring to use a weapon of mass destruction.
“The big unknown” is what Tsarnaev did during his trip to Russia, said Rogers, the House Intelligence Committee chief.
After a tip-off by the Federal Security Service (FSB), the main successor to the Soviet KGB, the FBI conducted a review of Tsarnaev’s activities, including interviews with family members and examinations of their communications and Internet usage, according to two U.S. law-enforcement officials who asked not to be named because the investigation is continuing.
After the FBI found nothing incriminating, the bureau asked Russia three times for any additional information that may be helpful and got no response, Rogers said.
Kurbanov, who previously coordinated the Dagestani government’s work with law enforcement, said cooperation between Russian and U.S. agencies hasn’t been “good enough” and the Americans should have been more attentive to Russian warnings. Rep. Mike McCaul, a Texas Republican who chairs the House Homeland Security Committee, faulted a lack of communication between U.S. agencies for the FBI’s failure to scrutinize Tsarnaev after his trip to Dagestan.
Putin, a former KGB officer, defended the FSB’s handling of the case, saying April 25 that the agency was unable to provide “information that would have operational significance” because Tsarnaev didn’t live in Russia.
Still, President Barack Obama thanked Putin for Russia’s cooperation in the probe during a phone conversation April 29, according to a White House statement.
In reality, Rogers said, the FSB has been withholding what it knows from its U.S. counterparts.
“I think they have information that would be incredibly helpful that they haven’t provided yet,” Rogers said. “You have to remember the FSB is a hostile service to the FBI and the CIA. There’s a cultural problem there between where the Russians are and our folks.”