Luxembourg prime minister Xavier Bettel speaks with British prime minister Teresa May at an EU meeting in Brussels, in January 2017 Prime Minister’s Office (Crown Copyright)

Luxembourg prime minister Xavier Bettel speaks with British prime minister Teresa May at an EU meeting in Brussels, in January 2017 Prime Minister’s Office (Crown Copyright)

Luxembourg's prime minister had arranged an official visit to London on Wednesday 22 March to meet May to discuss EU politics.

On Wednesday, around 3:40pm Luxembourg time, one man was shot after he stabbed a policeman outside the House of Commons, and several people were injured when he ran his car into people on Westminster bridge.

British police said on their website that they would treat this, until further notice, as a "terrorist incident".

Parliament is reportedly in lockdown and the tube station is also closed.

Luxembourg's government announced that the meeting had been called off at 5:15pm.

A Downing Street source said Theresa May was safe, the BBC reported.