NAJAF, Iraq -- A Shi'ite Muslim insurgency appeared to be weakening last night as Iraqi forces moved to within 200 yards of the revered Imam Ali Shrine and Iraq's defense minister once again demanded fighters loyal to a radical cleric surrender or face a violent raid.
The militant force, which once waged fierce battles with US troops throughout the Old City and Najaf's vast cemetery, seemed considerably diminished in number and less aggressive after days of US airstrikes and relentless artillery pounding.
Hundreds of insurgents have been spotted leaving Najaf in recent days, witnesses said. Those that remained appeared to have pulled back to the area around the shrine, where the fighting yesterday was concentrated, US troops said.
Police say radical Shi'ite cleric Moqtada al-Sadr, who has not been seen in public for days, has fled the city.
His aides, however, vigorously denied that, saying Sadr was in a secret hide-out in Najaf. Regardless, the fiery cleric's absence from the battlefield may have withered his followers' morale.
US warplanes bombed the Old City late yesterday for the third night in a row, witnesses reported. Huge blasts rumbled for about 10 minutes followed by gun battles and smaller explosions.
Earlier in the day, fierce fighting broke out near the shrine compound, with rockets launched from US helicopters kicking up clouds of smoke and debris. Bradley fighting vehicles patrolling the nearly deserted, bullet-scarred streets attacked militants, who responded with mortar fire and rocket-propelled grenades.
''We are under constant enemy small-arms, mortar, and RPG attack," said US Lieutenant Chris Kent, whose unit was about 300 yards from the compound.
Iraqi forces, accompanying US troops into the Old City for the first time in recent days, combed through the neighborhood, approaching as close as 200 yards to the shrine, controlled by militants loyal to Sadr.
Both the Iraqi government and the US military say no military moves are being made without the approval of interim Prime Minister Ayad Allawi.
Defense Minister Hazem Shaalan, addressing Iraqi National Guard troops in Najaf, said yesterday that Iraqi forces would head toward the shrine during the night to await the signal for a raid or the capitulation of the militants.
''When your brothers approach the holy shrine compound, they will direct calls of mercy to those [militants] to surrender," Shaalan told the troops. ''They have hours to surrender."
By late yesterday, there was no indication Iraqi forces had advanced on the shrine.
Shaalan made a similar threat a week ago, saying the government could raid the shrine by the end of the day last Wednesday to free it of ''its vile occupation." The government later backed down and said it would work for a peaceful solution.
Any raid on the shrine, the holiest Shi'ite site in the country, risked igniting a massive Shi'ite rebellion throughout Iraq against the fledgling interim government, already battling a persistent and bloody Sunni Muslim insurgency.
''I tell Shaalan to throw his new declaration in the same garbage that he already threw his earlier declarations in," Sadr aide Sheik Aws al-Khafaji told Al-Jazeera television. But other Sadr lieutenants reiterated their appeal for talks, a request the government has repeatedly rejected.
''We are ready to negotiate to end this crisis and the suffering of our persecuted people . . . but this government doesn't want negotiations," said Sheik Ali Smeisim, a senior Sadr aide.
The militants have repeatedly accused US forces of damaging the shrine during the fighting. The US military accused the militants of launching attacks from holy sites, but said it has restrained itself from attacking those positions.
The military released aerial photos yesterday purportedly showing a complete militant mortar system set up just outside the shrine compound.
Iraqi officials have said that any raid on the shrine would be conducted by Iraqi forces, since the presence of US troops at the holy site would inflame Shi'ites.
In other violence, witnesses and a hospital official said US aircraft attacked targets in Fallujah early today, killing three people. US forces have launched several air strikes in recent months on buildings in Fallujah reportedly used by fighters linked to al Qaeda ally Abu Musab al-Zarqawi.
Also yesterday, clashes between British forces and Sadr militants in the southern city of Amarah killed eight people and injured 18 others, said Dr. Saad Hemood of the Zahrawi General Hospital.
The fighting started when militants attacked a British foot patrol with small arms and fired mortar rounds, residents said.
Residents said British warplanes bombed the city, but Squadron leader Spike Wilson, a British military spokesman, said no planes were used in Amarah and he had no reports of coalition casualties.
In southern Baghdad, a car bomb exploded in the Qadisiyah neighborhood as Environment Minister Miskhat Moumin was passing through in a convoy, ministry spokeswoman Dalal Ali said. Moumin escaped unharmed, Ali said. Four bodyguards were killed in that blast, said an Interior Ministry spokesman, Colonel Adnan Abdul-Rahman. A suicide bomber was also killed.
In a second attack about the same time in western Baghdad, a bomb exploded beside Education Minister Sami Mudhafar's convoy, killing one of his bodyguards and wounding two others, police said.
The convoy was heading to work at the time and the minister was not injured, a bodyguard who survived the attack said.
In a statement posted on an Islamic website, Jordanian militant Abu Musab al-Zarqawi's Tawhid and Jihad group purportedly claimed responsibility for the attack on Moumin.
Insurgents have repeatedly targeted top officials for assassination, accusing them of collaborating with US forces here.
Also in Baghdad, assailants fired a rocket-propelled grenade at a US patrol on Monday night, killing one soldier and wounding two others, the military said yesterday.
Also yesterday, a militant group calling itself ''The Islamic Army in Iraq" said it had kidnapped Italian journalist Enzo Baldoni and could not guarantee his safety unless Italy announced within 48 hours it would withdraw its 3,000 troops, according to a statement sent to Al-Jazeera.