FILE - In this Monday, July 8, 2013 file photo, an airplane of Aeroflot flight rolls out in preparation for a takeoff seen through a window of Sheremetyevo airport outside Moscow, Russia. The U.S. Homeland Security Department is warning airlines flying to Russia that terrorists may try to smuggle explosives on board hidden in toothpaste tubes. The threat was passed onto airlines that have direct flights to Russia, including some that originate in the United States, according to a law enforcement official speaking Wednesday, Feb. 5, 2014 on condition of anonymity because he was not authorized to discuss details of the warning. (AP Photo/Alexander Zemlianichenko, file)