The militant Shiite cleric whose uprising last April left hundreds dead pledged Sunday to resist "oppression and occupation" and calling the new interim Iraqi government "illegitimate."

Muqtada al-Sadr (search) made the declaration in a statement distributed by his office in the Shiite holy city of Najaf, where his al-Mahdi militia battled American troops until a cease-fire last month.

"We pledge to the Iraqi people and the world to continue resisting oppression and occupation to our last drop of blood," al-Sadr said. "Resistance is a legitimate right and not a crime to be punished."

Previously, Al-Sadr had made conciliatory statements to the new government of Prime Minister Iyad Allawi (search), a fellow Shiite, and members of his movement had suggested they might transform the al-Mahdi Army (search) into a political party. Also, Al-Mahdi fighters accepted cease-fires in most Shiite areas after suffering huge losses at the hands of the Americans.

However, in his statement Sunday, the young cleric said, "There is no truce with the occupier and those who cooperate with it."

"We announce that the current government is illegitimate and illegal," al-Sadr said. "It's generally following the occupation. We demand complete sovereignty and independence by holding honest elections."

On June 12, al-Sadr issued a statement saying he was ready for a dialogue with the new government if it worked to end the U.S. military presence.

It was unclear what prompted his apparent reversal, though al-Sadr has made contradictory statements in the past. Earlier Sunday, Allawi told ABC's "This Week" that he had met with al-Sadr representatives "who want to try and mediate."

"The position of the government is very clear," Allawi said. "There is no room for any militias to operate inside Iraq. Anything outside law and order is not tolerated, cannot be tolerated. The rule of law should prevail. Every one of us, every individual, starting from the president downward should be answerable to the law."

Al-Sadr launched his rebellion after the U.S.-led coalition administration closed his newspaper, arrested a top aide and announced a warrant charging him in the April 2003 murder of a rival cleric.

After nearly eight weeks of fighting, the Americans announced that they would leave it to the Iraqi government to deal with al-Sadr, including serving the arrest warrant.

The harsh statement Sunday suggested the government may be taking a hard line with al-Sadr, insisting he abolish his militia and submit to the warrant.

Meanwhile, violence continued throughout Iraq on Sunday as Iraqi troops thwarted a car bombing outside their regional headquarters northeast of Baghdad, killing an attacker before could detonate his vehicle. Two bystanders also died in the assault in Baqouba, the scene of fierce fighting last week between American soldiers and insurgents who tried to seize government buildings and police stations.

Iraqi officials have blamed foreign fighters and religious extremists for a wave of vehicle bombings in recent months. The attacks have led to fears that religious fanatics and Saddam Hussein loyalists may be joining forces to fight both the multinational force and the new Iraqi government.

Saboteurs also blew up part of a strategic crude oil pipeline that runs from the country's northern oil fields to the south, police officials said. Fire crews and police from at least three nearby cities worked into the night to extinguish the blaze near Musayyib, about 50 miles southwest of Baghdad. Pipelines in that area have been hit several times in the past few weeks.

Between Baghdad and the restive city of Fallujah, insurgents fired rocket-propelled grenades and automatic weapons at a U.S. convoy of 20 gasoline tankers. There were no reports of casualties.

In Kirkuk, U.S. and Iraqi forces detained six members of a militant group suspected of a string of assassinations in the north. The men were believed to be members of Ansar al-Islam, a Kurdish group believed linked to Al Qaeda, said Iraqi police Col. Sarhat Qader.

The fate of Cpl. Wassef Ali Hassoun, a kidnapped U.S. Marine of Lebanese origin, remained unclear. A Web site statement Saturday attributed to the Ansar al-Sunna Army said he had been killed. But on Sunday, the group issued a statement on its own Web site saying the earlier declaration was false.

Hassoun's abduction was first reported June 27, when the Arab television station Al-Jazeera broadcast a videotape showing him blindfolded. A statement from militants threatened to kill him unless the United States released all Iraqis in "occupation jails."

Although Iraq regained sovereignty last Monday, about 160,000 foreign troops, most of them Americans, remain here under a U.N. resolution to help the new government restore security.

On Sunday, Allawi politely but firmly rejected troop offers from Jordan's King Abdullah II, telling ABC's "This Week" that "we are not asking" for additional soldiers.

The Iraqis are not eager to bring in Arab troops — especially from neighboring countries — fearing it could complicate relations with Syria and Iran, which U.S. and Iraqi officials have alleged have not done enough to control infiltration across their borders.

Allawi's government is expected to announce a package of initiatives to combat the insurgency, including limited emergency rule and an amnesty offer.

Allawi's spokesman, Georges Sada, suggested Saturday that guerrillas who fought the Americans before the sovereignty transfer could be eligible because they had taken legitimate acts of resistance.

However, the deputy prime minister for national security, Bahram Saleh, said in a televised interview that he found the comment "very surprising to have come from a spokesman for the prime minister."

Saleh confirmed the Cabinet was discussing an amnesty offer and was deliberating how to give "people an opportunity to reintegrate within society" while at the same time "remaining firm against people who have committed atrocities and have committed crimes against the people of Iraq and against the coalition forces that have come to help us overcome tyranny."