Thousands of US troops and Iraqi soldiers launched a major assault yesterday on militiamen loyal to a radical Shiite cleric in Najaf, with explosions and gunfire echoing near the holy city's revered Imam Ali shrine and its cemetery.

　　Meanwhile, Iraqi Minister of State Qassim Dawoud said yesterday that Iraq will hold its delayed national conference on Sunday. The conference, considered a key step on the road to democracy, was to have been held last month, but was delayed after many important factions said they planned to boycott it.

　　The coalition forces were trying to crush an uprising led by cleric Muqtada al-Sadr, whose fighters have been battling US troops in Shiite strongholds across Iraq for a week. Hundreds of people have fled in the last few days, moving in with relatives and friends in quieter neighborhoods, or out of Najaf entirely.

　　"Major operations to destroy the militia have begun," said US Marine Major David Holahan, executive officer of the 1st Battalion, 4th Marines Regiment. He said thousands of US troops were taking part.

　　Huge plumes of black smoke rose up from the city yesterday afternoon.

　　Minutes before, US military Humvees headed toward al-Sadr's house and fought with the militants guarding the building, witnesses said. A large fire raged across the street and at least two helicopters were seen flying above the area.

　　US officials have said in recent days they had no plans to arrest al-Sadr.

　　A column of US tanks lined one edge of the cemetery, as a helicopter flew overhead on patrol. Soldiers crawled on the roofs of single-story buildings, setting up positions.

　　The Najaf fighting yesterday killed at least five civilians, according to Nabil Mohammed, a health worker in Najaf. Two soldiers were injured when hit by a mortar shell while standing in an intersection on the edge of the cemetery, the military said.

　　Meanwhile, fighting by insurgents and al-Sadr supporters against Iraqi forces killed at least 72 Iraqis in the southern city of Kut, 160 kilometers southeast of Baghdad.

　　Iraqi forces fought off the militants who targeted the city hall, police stations and Iraqi National Guard barracks in Kut.

　　Residents said US and Iraqi forces chased militants into the local neighborhoods; the US military said only Iraqi forces were involved in the fighting on Wednesday in Kut.

　　Iraq's Health Ministry said 75 were killed in the fighting; provincial health official Falah al-Bairaman said 72 were killed and 148 injured.

　　The offensive in Najaf risked enraging Iraq's Shiite majority - including those who do not support the uprising - if it targets the shrine, where many of the insurgents have taken refuge.

　　Elsewhere, Iraq's main southern crude export pipeline began pumping oil again yesterday. Exports had been cut to almost half because of an attack on the pipeline.

　　(AP/Reuters)