OTTAWA - A man was detained by police this morning not far from Stephen Harper as the prime minister stopped by the National War Memorial to pay tribute to Cpl. Nathan Cirillo.

No other details were immediately available.

Harper visited the memorial to lay a wreath where Cirillo was fatally shot Wednesday by a gunman who then raced to Parliament Hill, where he was killed in a gunfight in the halls of the Centre Block.

As the prime minister arrived, police could be seen wrestling a man to the ground and cuffing him before taking him to a nearby police cruiser.

Several federal MPs were also on hand to pay their respects, even taking part in an impromptu rendition of O Canada.

Harper and the rest of the MPs are expected to be in the House of Commons to resume the business of government.