BAGHDAD, May 22 (Reuters) - Iraq's top Shi'ite cleric, Grand Ayatollah Ali al-Sistani, called on Friday for a "wise and precise" plan to purge the country of Islamic State militants after they overran the western provincial capital of Ramadi several days ago.

In his first sermon since the fall of Ramadi, Sistani's representative Sheikh Abdulmehdi al-Karbalai, did not refer explicitly to the city. But he said: "We must have a precise and wise plan drawn up by professional and patriotic figures... to resolve the military and security issues and begin to purge Iraqi lands of all terrorists." (Editing by Hugh Lawson)