The aftermath of the Boston Marathon explosions last week. Photo: Aaron Tang/Wikimedia Commons.

As the aftermath of the Boston Marathon bombings continues to unfold, investigators are looking into extremist ties between Tamerlan Tsarnaev and his mother, Zubeidat Tsarnaeva, including a suggestion by his mother that he travel to “Palestine” to conduct possible terrorist activities there.

New wiretap evidence provided by the Russian Federal Security Service (FSB) to the FBI suggests possible extremist influence by the mother of the two bombers, Tamerlan and Dzhokar.

In early 2011, the FSB had intercepted a called between Tamerlan and his mother, Zubeidat, where the two vaguely discussed jihad, U.S. officials told the Associated Press.

Part of the discussion involved the possibility of Tamerlan traveling to the Palestinian territories. But Tamerlan expressed doubts to his mother, saying he did not know the language there.

As a result, the Federal Bureau of Investigation is investigating Zubeidat Tsarnaeva’s influence over her sons.

“Intelligence officials have also found text messages in which the mother discusses how Tamerlan is ready to die for Islam,” Newsday reported, citing two anonymous sources.