LONDON, Aug 6: Iraq's top Shia leader Grand Ayatollah Ali al Sistani arrived in London on Friday for treatment for a heart condition. The influential scholar, who has been a voice of moderation in Iraq, landed at Heathrow airport aboard a scheduled flight from Beirut.

The Middle East Airlines jet taxied to a point away from Heathrow's terminal three and Ayatollah Sistani, dressed in black robes, walked down the steps and into a limousine while armed police stood guard.

Airport sources said he was heading for an unnamed hospital in central London. During a brief stopover in Beirut where he changed planes, officials said the 73-year-old ayatollah was able to walk with some help. There had been fears fighting in the holy city of Najaf, where he lives, could hamper his access to proper medical care.

One of Ayatollah Sistani's aides said on Thursday it was the first time he had experienced heart problems. The reclusive Iranian-born Sistani holds huge sway over Iraq's Shias despite rarely speaking in public and not having left Najaf, south of Baghdad, for years.

He played a leading role in striking a cease-fire that halted fighting in April and May between the Mehdi Army militia of firebrand Shia leader Moqtada al Sadr and American troops across southern and central Iraq.

In June, Ayatollah Sistani gave conditional approval to Iraq's interim government, saying it lacked "electoral legitimacy" but was a step in the right direction. His non-confrontational but firm approach to US-led occupation forces has appealed to many Shias. -Reuters