The escalating crisis in Ukraine has hit the European markets, which have seen a major slump amid worries the tensions will force higher energy prices if economic sanctions come into effect.
Traders remain wary that a worsening conflict could affect Russia's supply of oil to the EU, two thirds of which is piped through Ukraine.
Oil prices surged by around 2% to above 104 US dollars a barrel in New York while the FTSE 100 Index was off by more than 1.5% at below 6700.
Other leading European markets suffered bigger falls, with the Dax in Frankfurt down by more than 2.5%.
More top news
The family of the police officer who was murdered in the Westminster attack have thanked those who were with him 'in his last moments'.
Thousands of fans gathered for a public memorial honoring famous mother and daughter who died just a day apart.
More sunshine this Sunday