EDINBURGH 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.
Separately, on Thursday two suspicious packages were also intercepted at police offices. One, in Glasgow was still being investigated. The second, in Fife, was not a threat, Police Scotland said in a statement.
It was not clear if the political security incidents earlier in the week were related and officials at Police Scotland were not available to comment.
The Scottish parliament said 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.
On Tuesday, police 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.
Local media reported one package was sent to the SNP's headquarters in Edinburgh and another to a local council building in the Scottish town of Forfar.
Officials at the SNP declined to comment.
Separately, Labour Party lawmaker Peter Hain, who represents an area in Wales, confirmed via text to Reuters a report in the Guardian newspaper that police were investigating a letter sent to him containing white powder. Police were not immediately available to comment.
Britain will hold 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 .
(Reporting by Elisabeth O'Leary, editing by Larry King; editing by Estelle Shirbon)