BAGHDAD, 4 October 2003 — US forces said they were digging in for a protracted struggle against a more “lethal” Iraqi resistance, while they faced growing calls yesterday to leave the country amid fresh violence in which two Iraqi attackers died.

Meanwhile, more than 10,000 Iraqis gathered in Najaf by the grave of Ayatollah Mohammad Baqer Hakim to mark the end of the official mourning period for the influential cleric, killed along with 82 others in a car bombing on Aug. 29.

The top US commander in Iraq, Lt. Gen. Ricardo Sanchez, admitted following a spate of deadly attacks this week that US forces were facing a deadlier foe than when they toppled Saddam Hussein six months ago.

“The enemy has evolved and he is a little more lethal, a little more complex, a little more sophisticated and in some cases a little more tenacious,” Sanchez said Thursday.

The danger of the enemy “has increased a little bit because they are using more improvised explosives against us... So he has evolved, he is learning, but so are we and this will continue for a little while,” he said. Every week, between three and six US soldiers were being killed and another 40 were wounded, Sanchez said.

He added that the resistance had expanded from pro-Saddam loyalists to a steady flow of foreign “terrorists” slipping into Iraq from Syria and northern Iran. Nevertheless, he said, his soldiers would not leave Iraq anytime soon. “It will definitely be years. We never said it would be anything less than years,” Sanchez told reporters.

In the northern city of Kirkuk, the US military said yesterday that two Iraqis were killed by an explosion, but would not confirm local reports they were failed suicide bombers.

The blast went off as US troops approached two Iraqis trying to plant an “improvised explosive device (IED)” late Thursday, said a US military spokesman who asked not to be named. “The IED exploded, killing the two Iraqis,” he said. He could not give any further details.

In Najaf, a sea of people gathered by Hakim’s grave to commemorate the approach of the 40th day of mourning for the slain cleric who had preached a moderate message in the tumult and chaos of postwar Iraq. They carried posters of Hakim and shouted the name of the late cleric’s brother, Abdel Aziz Hakim, who succeeded his sibling as head of the prominent Shiite political party, the Supreme Council for the Islamic Revolution in Iraq.

“Aziz, you are the leader,” the crowd chanted, as green and black flags fluttered in the air by Hakim’s mausoleum at Revolution Square in the heart of Najaf, 180 kilometers south of the capital. But prayer leader Sadreddin Al-Qobanshi also called for “the speedy withdrawal of occupation forces,” from Iraq — a demand repeated at weekly Friday sermons across the country.

“The drafting of a permanent constitution for the country must be done by a panel elected by the Iraqi people,” Abdel Aziz said at the mourning ceremony. “It must be ratified through a nationwide referendum,” he said. A group of Saddam supporters, meanwhile, also rallied northeast of Baghdad to renew their allegiance to their fallen leader and call for the end to the occupation, an AFP correspondent and witnesses said.