WASHINGTON (AP) - Two government officials have said that U.S. intelligence agencies added the Boston bombing suspects' mother to a federal terrorism database about 18 months before the attack.

Officials say this was done after Russia contacted the CIA late in 2011 with concerns that the now-dead suspect, Tamerlan Tsarnaev, and his mother, Zubeidat Tsarnaeva, were religious militants about to travel to Russia.

The CIA asked that Tsarnaev and Tsarnaeva be added to a classified intelligence database called TIDE. Being on the database does not automatically mean the U.S. suspects a person of terrorist activity and does not automatically subject a person to surveillance, security screening or travel restrictions.

The officials spoke on condition of anonymity because they were not authorized to speak publicly about the investigation.