Al-Muhajir, an Egyptian also known as Abu Ayyub al-Masri, boasted that al-Qaida in Iraq is moving toward victory faster than expected because of Bush's mistakes.
White House spokesman Tony Snow said the Bush administration had no comment on the tape.

The tape and its often far-fetched claims came as the U.S. military announced the deaths of five more service members in the 44-month-old conflict, which has grown increasingly unpopular at home. Twenty-six American service members have been killed in Iraq so far this month.

At least 59 Iraqi civilians were killed or found dead Friday as the violence threatens to spiral into all-out civil war. In one of the day's bloodiest incidents, a suicide bomber in an explosives-rigged car killed six Iraqi soldiers he had lured from behind a checkpoint.
Just hours earlier, Iraq's army said it captured the Egyptian leader of an al-Qaida cell in Anbar province, an insurgent stronghold.

The audio message appeared to be an attempt to exact maximum propaganda benefit from the results of Tuesday's midterm elections, in which the Republicans lost control of both houses of Congress, in part because of the war.

Al-Muhajir praised the American people for handing victory to the Democrats, saying: "They voted for something reasonable in the last elections."

He also said Bush was "the most stupid president" in U.S. history.

"We call on the lame duck not to hurry his escape the way the defense secretary did," al-Muhajir said in reference to Rumsfeld's resignation as Pentagon chief on Wednesday.

"Remain steadfast on the battlefield, you coward," said al-Muhajir, who took over leadership of al-Qaida in Iraq after Abu Musab al-Zarqawi was killed in a U.S. airstrike in June.

"We will not rest from our jihad (holy war) until we are under the olive trees of Rumieh and we have blown up the filthiest house - which is called the White House," al-Muhajir said.

The "olive trees of Rumieh" appeared to be a reference to the Mount of Olives in Jerusalem, or to Christendom as a continuation of the Roman empire.

Al-Muhajir also told Iraqi Sunnis to ally with a shadowy mini-state that militants claim to have established last month under a man identified as Abu Omar al-Baghdadi.

"I vow allegiance to you," he said, addressing al-Baghdadi as the "ruler of believers " and placing al-Qaida in Iraq fighters under his command.

Friday's civilian death toll was little changed from previous days. The United Nations estimates about 100 Iraqis die in violence each day, while Iraq's health minister on Thursday estimated up to 150,000 civilians had been killed in the war - about three times previously accepted estimates of 45,000-50,000.

At least 33 bodies were found Friday, most the victims of roving sectarian death squads that usually torture their victims before shooting them.

Among the latest victims was a Sunni imam, Akram Jassim, 60, gunned down at the front entrance to his mosque in Mosul, 225 miles northwest of Baghdad, said Brig. Abdul Kerim al-Jubori, a spokesman for the provincial police.

Meanwhile, Bush and his national security team will meet Monday with members of a blue-ribbon commission trying to devise a new course for the unpopular war.

The bipartisan Iraq Study Group, led by former Secretary of State James A. Baker III and former Democratic congressman Lee Hamilton of Indiana, is expected to report its recommendations before the end of the year.

Members of the group will have a joint conference at the White House with Bush, Vice President Dick Cheney and National Security Adviser Stephen Hadley.