The United States has tightened restrictions on travellers arriving from the West African countries gripped by an Ebola outbreak, funnelling them into five airports with extra health checks.
The Department of Homeland Security on Tuesday ordered passengers whose journeys begin in Guinea, Liberia or Sierra Leone to fly to New York's JFK or Newark airports, Washington Dulles, Atlanta or Chicago.
There are no direct scheduled flights to the United States from the three countries at the heart of the Ebola epidemic, but travellers from the region can transfer through African and European hubs.
One Liberian with Ebola arrived in Dallas, Texas and infected at least two US health workers before dying, piling pressure on President Barack Obama's government to impose a flight ban.
Health authorities have set up additional screening for passengers at five airports which they say normally handle 96 per cent of the travellers arriving from the three worst hit countries.