British Airways and airport authorities have tightened security measures for US-bound flights following reports that a Nigerian person attempted to blow up a plane.<br/><br/>"The United States government has revised its security arrangements for all passengers travelling into the US. This includes additional screening of all US-bound passengers and hand luggage before they board their flights, this applies to all carriers," a British Airways statement said in London.<br/><br/>"Passengers travelling to the US will only be allowed to carry one item of hand luggage. We apologise to passengers for any delays to their journeys. Safety and security are our top priorities and will not be compromised," it said.<br/>