Alaska Airlines has banned 14 passengers after unruly behavior on a flight Thursday from Washington, DC that included refusing to wear a mask. The sanction came as security was increased at Washington-area airports after reports of rowdy behavior by supporters of outgoing president Donald Trump flying into the city earlier in the week and the subsequent siege of the US Capitol building. A large group of Trump supporters stormed the seat of US democracy in widely condemned violence that has claimed at least five lives. READ: Australia mandates pre-flight COVID testing, cuts arrival caps. Reuters quoted Alaska as saying the passengers on the flight to Seattle from Washington-Dulles airport as “non-mask compliant, rowdy, argumentative and harassed our crew members”. “Because of their actions and non-compliance we have banned 14 of those passengers from future travel with us,’’ it said. It was not clear whether the banned passengers took part in the Trump riot but unions representing flight attendants had previously expressed concern about the behavior on flights of supporters as they headed to the event. At least one carrier, American Airlines, suspended alcohol services on outbound flights. Association of Flight Attendants -CWA international president Sara Nelson, who represents flight attendants from 17 airlines, labeled the “mob mentality” of some passengers  unacceptable and said it “threatened the safety and security of every single person on board”. “There’s a reason that there are strict penalties and fines for failing to comply with crew member instructions,” she said. “Enforcement keeps everyone safe.” Nelson warned that the Capitol Hill violence created further concern about the departure from the D.C area of those who participated in the riot. “We in aviation have a serious role to play in national security. Airlines, in coordination with TSA, DHS, FAA, DOT and law enforcement must take all steps to ensure the safety and security of passengers and crew by keeping all problems on the ground,” she said. The Association of Professional Flight Attendants, which represents cabin crew at American,  also expressed concern about politically motivated incidents onboard aircraft, saying it had been a problem in the past few days and this was expected to continue into the weekend. "Regardless of one's political beliefs, the cabin of a commercial aircraft must, out of necessity, be a calm environment for the safety of everyone on board," AFPA president Julie Hedrick said in a statement.