Three oil protesters held, say they scale roof of UK parliament
* Police arrest three protesters at parliament in London
* Demonstrators target visit by Canadian prime minister
* Organisers say tar sands activists scaled roof
By Peter Griffiths
LONDON, June 13 (Reuters) - British police arrested three environmentalists on Thursday after protest organisers said they scaled the roof of parliament during a visit by Canadian Prime Minister Stephen Harper, in an embarrassing security breach before Britain hosts a G8 summit.
Two men and a woman were held on suspicion of trespassing on a protected site minutes before Harper gave a speech to both Houses of Parliament as part of his visit to Britain, London's police force said in a statement.
Harper was in London before attending a G8 meeting in Northern Ireland with British Prime Minister David Cameron, U.S. President Barack Obama and other world leaders on June 17-18.
Organisers of a protest against Canada's extraction of crude from oil sands said members of their group had managed to scale the roof of the parliament building in Westminster. Police said they were aware of reports the group had climbed on to the roof.
Two more protesters were arrested outside one of the main entrances to parliament on suspicion of criminal damage. Protesters said they had thrown molasses, a dark heavy syrup that looks like oil, onto the floor. Continued...