WASHINGTON - The FBI is investigating in the United States and overseas to determine whether the suspects in the Boston Marathon bombing received training that helped them carry out the attack, the chairman of the U.S. House Homeland Security Committee said Sunday.
Rep. Michael McCaul spoke a day after U.S. officials disclosed that Russian authorities secretly recorded a telephone conversation in 2011 in which one of the two brothers suspected in the attack, Tamerlan Tsarnaev, vaguely discussed jihad with his mother.
The father of the Tsarnaev brothers, meanwhile, said from Russia on Sunday he is postponing a trip to the U.S. because of poor health.
Tsarnaev, 26, died in a police shootout. His younger brother, 19-year-old Dzhokhar, is charged with setting off the shrapnel-packed pressure-cooker bombs near the finish line of the Boston Marathon on April 15. Three people were killed and more than 260 were injured.
U.S. officials investigating the bombings have told The Associated Press that so far there is no evidence to date of a wider plot, including training, direction or funding for the attacks.
The bombs were triggered by a remote detonator of the kind used in remote-control toys, U.S. officials have said. A criminal complaint outlining federal charges against Dzhokhar Tsarnaev described him as holding a cellphone in his hand minutes before the first explosion.
The brothers are ethnic Chechens from Russia who came to the United States about a decade ago with their parents.
"I think given the level of sophistication of this device, the fact that the pressure cooker is a signature device that goes back to Pakistan, Afghanistan, leads me to believe — and the way they handled these devices and the tradecraft — ... that there was a trainer and the question is where is that trainer or trainers," said Rep. Michael McCaul, a Republican, on "Fox News Sunday."
"Are they overseas in the Chechen region or are they in the United States?" McCaul said. "In my conversations with the FBI, that's the big question. They've casted a wide net both overseas and in the United States to find out where this person is. But I think the experts all agree that there is someone who did train these two individuals."
At this point in the investigation, however, Sen. Claire McCaskill said there was no evidence that the brothers "were part of a larger organization, that they were, in fact, part of some kind of terror cell or any kind of direction."
The Democrat, who's on the Senate Homeland Security and Governmental Affairs Committee, told CBS' "Face the Nation" that "it appears, at this point, based on the evidence, that it's the two of them."
Homemade bombs built from pressure cookers have been a frequent weapon of militants in Afghanistan, India and Pakistan. Al-Qaida's branch in Yemen once published an online manual on how to make one.
U.S. officials said Saturday that in the past week, Russian authorities have turned over to the United States information it had on Tamerlan Tsarnaev and his mother, Zubeidat Tsarnaeva.
In early 2011, the Russian FSB internal security service intercepted a conversation between Tamerlan and his mother vaguely discussing jihad, according to U.S. officials who spoke on condition of anonymity because they were not authorized to discuss the investigation with reporters.
The two discussed the possibility of Tamerlan going to Palestine, but he told his mother he didn't speak the language there, according to the officials, who reviewed the information Russia shared with the U.S.
In a second call, Zubeidat Tsarnaeva spoke with a man in the Caucasus region of Russia who was under FBI investigation. Jacqueline Maguire, a spokeswoman for the FBI's Washington Field Office, where that investigation was based, declined to comment.
There was no information in the conversation that suggested a plot inside the United States, officials said.
The conversations are significant because, had they been revealed earlier, they might have been enough evidence for the FBI to initiate a more thorough investigation of the Tsarnaev family.
As it was, Russian authorities told the FBI only that they had concerns that Tamerlan and his mother were religious extremists. The FBI opened a preliminary investigation but the scope was extremely limited under the FBI's internal procedures.
After a few months, they found no evidence Tamerlan or his mother were involved in terrorism.
The FBI asked Russia for more information. After hearing nothing, it closed the case in June 2011.
In the fall of 2011, the FSB contacted the CIA with the same information. Again the FBI asked Russia for more details and never heard back.
At that time, however, the CIA asked that Tamerlan's and his mother's name be entered into a massive U.S. terrorism database.
The CIA declined to comment Saturday.
It was not immediately clear why Russian authorities didn't share more information at the time. It is not unusual for countries, including the U.S., to be cagey with foreign authorities about what intelligence is being collected.
The FSB said Sunday that it would not comment.
McCaul said he thinks the Zubeidat Tsarnaeva played a "very strong role" in her sons' radicalization process and that she would be held for questioning if she were to return to the United States from Russia.
She has denied the family is involved in terrorism and says her sons were framed.
Ruslan Tsarni, an uncle of the Tsarnaev brothers and Zubeidat's former brother-in-law, said Saturday he believes the mother had a "big-time influence" as her older son increasingly embraced his Muslim faith and decided to quit boxing and school.
Anzor Tsarnaev, the father of the two suspects, told The Associated Press that he is postponing a trip to the U.S. because he is "really sick" and his blood pressure had spiked. He had planned to travel from Russia to the U.S. with the hope of seeing his younger son and burying his elder son.
Tsarnaev confirmed that he is staying in Chechnya, but did not specify whether he was hospitalized. Until Friday, he and the suspects' mother had been living in the neighbouring province of Dagestan.
Tamerlan Tsarnaev was an ardent reader of jihadist websites and extremist propaganda, officials have said. Officials say Dzhohkar told FBI interrogators that he and his brother were angry over wars in Afghanistan and Iraq and the deaths of Muslim civilians there.
Associated Press writer Arsen Mollayev in Makachakla, Russia, contributed to this story.