Baghdad ? Radical Shiite cleric Muqtada al-Sadr has decided whether to extend his Mahdi Army’s cease-fire, and sent the message in sealed envelopes to be opened at the beginning of today’s sermons, one of his officials said.

Although the content of the message, delivered Thursday to 200 loyal clerics around Iraq, was not known, there were strong indications from officials in his organization that the anti-U.S. firebrand would extend the six-month cessation of what had been an undeclared war against the U.S. military since 2004.

The cease-fire has been one of three important factors that have helped reduce violence since mid-2007. The two others are the influx of thousands of U.S. troops last summer and emergence of Sunni-dominated groups that are fighting against al-Qaida in Iraq.

In the latest violence, the U.S. military announced the deaths of five soldiers and a Marine. A roadside bomb wounded four British troops in the southeastern city of Basra, followed by clashes. Police and morgue officials also said a grave with 15 bodies was found in an orchard elsewhere in the same province.

The message from the elusive al-Sadr was expected to be read during prayers in the southern city of Kufa and in Baghdad’s Sadr City slum, both strongholds of his powerful Mahdi Army militia.

According to one Iraqi legislator loyal to al-Sadr, the message was sent with strict instructions not to open it until the midday weekly Islamic services.

The legislator, who spoke on condition of anonymity because he wasn’t authorized to release the information, told The Associated Press on Thursday that “tomorrow there will be a statement from Sayyid Muqtada to be read during Friday prayers.” Sayyid is an honorific.

“No one can predict what decision will be – whether it will be an extension of the freeze or not,” he said.

Earlier in the week, a Sadr spokesman had said that if the cleric failed to issue a statement, then the cease-fire would automatically be lifted.

In a show of force ahead of the expiration of the cease-fire, thousands of Mahdi Army members marched through the streets of Sadr City on Thursday, unarmed but dressed in black with green kerchiefs.