U.S. authorities are advising women not to wear gel bras on airplanes as information developed in the foiled London plot points to an expanding role for women in smuggling explosives on to an aircraft. Authorities at Scotland Yard are questioning a husband and wife, suspects in the London terror plot, about allegations that they were planning to use their baby’s bottle to hide a liquid bomb. Police in the U.K. have recovered baby bottles containing peroxide, including some with false bottoms, from a recycling center close to the homes of some of the arrested suspects. The use of female suicide bombers has been successful in previous airplane attacks. When two airplanes went down within minutes of each other in Russia in 2004, officials immediately suspected a terrorist connection. It was later learned that the two suicide bombers were Chechen women. They had both been detained in the airport before boarding their flights but managed to convince airline officials using a little cash and charm to let them on board. Ninety people were killed. "Black Widows," as they are called by the Russian media, are Chechen women who kill themselves to avenge the deaths of their husbands or other male family members. There are numerous other examples of the use of female operatives in terrorist operations. Two women with explosive belts were among the hostage takers during the siege of a middle school in Beslan, Russia. Over 300 people were killed; half of them were children. A woman had planned to blow herself up with her husband in an attack at a wedding in a hotel in Amman, Jordan last year that killed over 50 people. His explosive belt worked, while hers did not. Maddy Sauer contributed to this report.