Airline shares were among some of the worst-hit stocks on both sides of the pond today, as Donald Trump's travel ban to citizens of seven countries in the Middle East and North Africa began to sink in.
In the UK, International Airlines Group (IAG), which owns British Airways, Aer Lingus, Iberia and Vueling, fell almost two per cent to 488.5p in mid-afternoon trading. Meanwhile, EasyJet fell 1.3 per cent to 961.25p.
In the US, shares were harder hit, with Delta Air Lines, which part-owns Virgin Atlantic, sinking 3.9 per cent to $47.77 in mid-morning trading in New York, while American Airlines fell 6.2 per cent to $44.05. United Continental, which operates United Airlines, fell 5.6 per cent to $70.27.
The selloffs came as the FTSE 100 fell almost one per cent to 7,116 points - despite the pound falling 0.3 per cent against the dollar, to $1.2512.
In the US, the Dow Jones fell below 20,000 points for the first time since it broke records by rising above that level last week. It was down one per cent, at 19,893 points, in afternoon trading in New York, while the S&P 500 also fell one per cent, to 2,271 points.
"The latest executive order from US President Donald Trump... has prompted large scale sell-offs across the board," said Michael Hewson, chief market analyst at CMC Markets.
"Investors [in the US have woken] up to the downside of what a Trump presidency might mean for risky assets.
"The weekend's executive order to implement more stringent vetting procedures to visitors to the US from specific destinations, as well as a wider travel ban, could well be the beginning of this realisation, as investors shed their goldilocks blinkers.
"For all the early optimism about the so called “Trump trade” it would appear that for some the rose tinted glasses may well be starting to fall away as they digest this new entirely predictable turn of events."