The US Transportation Security Administration (TSA) has banned all liquids, gels, aerosols, and powders from direct flights between the United States and Russia. Delta Airlines posted a notice on its site notifying its customers of the rule change, which is effective immediately. The news comes on the heels of a report from the Department of Homeland Security that warned airlines to be on the lookout for explosives in toothpaste containers. Despite the warning, officials said that "we are not aware of a specific threat to the homeland at this time."

TSA rules already prohibit carry-on liquids, gels, and aerosols to no larger than 3.4 ounces per container (about 100mL), and all such products must be placed in a clear 1 quart (roughly 0.95 liter) bag for screening. The restriction was put in place back in 2006 in response to plots to explode airliners. Why those restrictions — designed to limit the amount of material that could be used to produce an explosive device — are not effective enough to counteract this latest threat is not clear. It's unknown if the restriction for direct flights between the US and Russia will be temporary, but it is similar to a move by the Russian government last month to ban liquids from carry-on bags in preparation for the Sochi Olympic Games.