EDINBURGH (REUTERS) - Three suspicious packages containing "white powder type substances" were sent to political offices between April 25 and 26, the Scottish parliament said in a statement on Thursday (April 27).

The packages were sent to an elected official, a political party headquarters and a local council building. Police were investigating and further advice has been issued to elected representatives across Scotland, the devolved assembly said.

Separately Labour Party lawmaker Peter Hain, who represents an area in Wales, confirmed via text to Reuters a Guardian newspaper report that police were investigating a letter sent to him containing white powder. Police were not immediately available to comment.

Britain is holding a national election on June 8 and earlier on Thursday police said a man carrying knives had been arrested not far from Prime Minister Theresa May's Downing Street office.

Last month a British-born convert to Islam ploughed a car into pedestrians on Westminster Bridge, killing four people, before stabbing to death a police officer in the grounds of parliament.

Police on Tuesday had said they were investigating a suspicious package sent to the East Dunbartonshire office of lawmaker John Nicolson, who represents the Scottish National Party at Britain's parliament in London.