WASHINGTON Russia asked the FBI in early 2011 to investigate Boston bombing suspect Tamerlan Tsarnaev out of concern he had embraced radical Islam and was going to travel to Russia to join underground groups, U.S. law enforcement sources said on Saturday.
Russia's Federal Security Service, or FSB, made a request for checks on Tsarnaev - who was killed after a shootout with police on Thursday - to help an investigation of its own, a U.S. government source said.
The Russians were not tipping off the FBI about a plot in the United States or any threat posed to U.S. interests, a law enforcement and national security source said on condition of anonymity.
The fact that there was no warning about an attack in the United States may help shield the Obama administration, spy agencies and law enforcement from criticism that they failed to see the danger from Tsarnaev, 26, and his younger brother, Dzhokhar, who are suspected of carrying out the twin bombings that killed three people and injured over 170 on Monday at the Boston Marathon.
Russia is battling Islamist militants in the volatile North Caucasus where the Tsarnaev brothers - who are ethnic Chechens - have family ties. But the number of tips from Moscow on possible terrorism cases is "not that many," a senior U.S. law enforcement source said.
The FBI said a foreign government had raised the alarm over Tsarnaev but did not comment on whether it was Russia. The bureau said it "did not find any terrorism activity, domestic or foreign" after interviewing Tsarnaev and his family, and checking his travel records and Internet activity in 2011. Those results were given to the foreign government in the summer of 2011, the FBI said.
The FBI found nothing to substantiate Russian allegations that Tsarnaev was a follower of radical Islam who was preparing to travel to Russia to join unspecified radical groups, a national security source said.
Tsarnaev flew to Russia the following year. Official records show he left New York's JFK airport on January 12, 2012 for Moscow and returned to the United States on July 17, 2012. It is unclear what he did while in Russia or whether he traveled elsewhere during that period.
Republican U.S. Representative Dana Rohrabacher said Tsarnaev may well have been trained overseas by "radical elements."
"The two young men directly involved in this terrorist attack were both Chechen and clearly influenced by radical Islam. One of them may well have been trained with terrorist weapons by radical elements overseas," said Rohrabacher, a member of the House of Representatives Committee on Foreign Affairs.
"The Chechen connection indicates we should work more closely with Russia and other nations who are also suffering the same kind of mayhem we have seen in Boston," he said.
Russian President Vladimir Putin has not commented on the identity of the two suspects, who moved to the United States more than a decade ago after briefly living in Russia's volatile southern region of Dagestan.
Instead, he and Obama made positive statements about cooperation on counterterrorism in a phone conversation on Friday, suggesting both sides see an opportunity to improve strained relations between their countries.
(Additional reporting by John Shiffman; Editing by Alistair Bell and Paul Simao)