Shares have tumbled after US President Donald Trump restricted travel to the US from mainland Europe in a bid to slow the spread of the coronavirus.
London’s FTSE 100 index sank more than 6%, with similar declines seen in other European markets.
Earlier, stocks in Asia saw big falls, with Japan’s benchmark Nikkei 225 index closing 4.4% lower.
It followed steep losses in US shares on Wednesday, with the Dow Jones plunging by 5.8%.
In the UK, some of the biggest fallers in the FTSE 100 included travel companies such as the airline group IAG, which sank by 11%, and travel company Tui, down 9%.
The FTSE 250 index – which tends to include more UK-focused companies – was more than 7% lower.
Elsewhere in Europe, indexes in Paris and Frankfurt also dropped nearly 7%.
Oil prices also fell, with Brent crude down more than 5% at $33.91 a barrel.
Source: BBC News