Coalition aircraft hit the Iraqi TV station in Baghdad Wednesday, knocking the state-run TV off the air, U.S. officials told Fox News.
• Map: The War in Iraq
Meanwhile, American infantry troops fought off a desert attack by Iraqis on Tuesday, inflicting heavy casualties in a clash less than 100 miles from Baghdad. British forces battled for control of Basra, a city of 1.3 million sliding toward chaos.
Defense officials said between 150 and 500 Iraqis were killed in the battle near An Najaf, adding there were no immediate reports of American casualties.
Iraqis launched their attack on a day of howling sandstorms -- weather bad enough to slow the U.S.-led drive toward the Iraqi capital.
After the sandstorm lifted in Baghdad, coalition aircraft struck the Iraqi state-run television channel, which U.S. military officials wanted to hit in order to cut communications links between Saddam Hussein and his military and the Iraqi people.
The state-run TV signal was lost around 4:30 a.m. after large explosions were heard in and around Baghdad. The pre-dawn raid came after a several-hours-long lull in allied bombing.
U.S. military officials told Fox News they were optimistic Iraq's state TV was down for the count. The channel could not be seen in Baghdad after the raid, but satellite transmissions continued with periodic breakups.
U.S. officials also told Fox News that the station's proximity to the Ministry of Information, which houses foreign media and is located a block away, raised concerns about collateral damage. But the TV station was a necessary target, they said, because it was believed the facility was being used as a meeting place by regime leadership and may have played a dual military/civilian role.
Meanwhile, Defense officials told Fox News Tuesday night that waterways to Umm Qasr — the Iraqi Persian Gulf port seized by coalition forces in recent days — should be clear of mines "today" so humanitarian aid could begin arriving.
But the port's piers were still mined and the British, who were leading the effort to clean up the port, estimated it will take at least another day to make the offloading points safe for cargo ships. If they are successful, the first humanitarian aid shipments should start arriving in Umm Qasr by Thursday. Umm Qasr will likely stay the center of humanitarian aid operations for the foreseeable future.
U.S. troops in control of a vast Iraqi air base sealed 36 bunkers, designated as possible hiding places for weapons of mass destruction.
American officials also issued fresh cautions about the possible use of chemical weapons by Iraqi troops, although none has yet been used in the 6-day-old war -- or even found by the invading troops.
As the pace of combat quickened, American and British officials sought to prepare the public for something less than a quick campaign, and predicted difficult days to come.
Still, President Bush forecast victory. The Iraqi regime will be ended ... and our world will be more secure and peaceful," he said after receiving a war update at the Pentagon.
Saddam saw it differently. State television carried what it described as a message from him to tribal and clan leaders, saying, "Consider this to be the command of faith and jihad and fight them."
If confirmed, the initial reports of fighting near An Najaf would make it the biggest ground clash of the war, as well as the first encounter between advancing American infantry and the Iraqi units guarding the approach to Saddam's seat of power.
A senior military official said the U.S. troops had hunkered down against a sandstorm when Iraqis -- either Republican Guard or paramilitary Iraqi troops traveling on foot -- opened fire with rocket-propelled grenades.
Some of the 7th Cavalry's equipment was damaged in the attack, the official said.
The unit is part of the Army force driving on Baghdad. Some elements of the force are farther north, near Karbala, with only the Medina armored division of the Republican Guard between them and Baghdad. Muslim clerics in Iran warned against military threats to shrines in Iraq. An Najaf is the burial place of Imam Ali, son-in-law of the Prophet Mohammed.
Details of the situation inside the southern city of Basra, Iraq's second-largest, also were sketchy. British journalists reported that residents were staging an uprising against pro-Saddam forces and that Iraqi troops were firing mortars at them.
British forces staged a raid on a suburb of the city, captured a senior leader of the ruling Baath party and killed 20 of his bodyguards.
"He's sitting there in his little room thinking he's having a good morning and whap, we're in, whap, we're out," boasted Col. Chris Vernon, a British Army spokesman.
A U.K. Centcom spokesperson told Fox News that British troops in Basra had taken out Iraqi mortars aimed at the civilian population during the recent uprising there.
Radar was used to locate the mortar rounds and effectively neutralize them, the spokesperson said.
And intelligence reports indicated Iraqi forces — either special Republican Guard or Fedayeen Saddam terrorists — in and around Basra were dressing up as U.S. soldiers, then accepting the surrender of other Iraqi forces and executing them, senior Defense officials told Fox News.
The Iraqis denied all of it. "The situation is stable," Information Minister Mohammed al-Sahhaf said in an interview with Al-Jazeera, an Arab satellite television network.
United Nations Secretary-General Kofi Annan and others have warned of a possible humanitarian crisis in Basra. The International Red Cross said during the day that it had begun repairs at a war-damaged water-pumping station serving the city.
Annan told Bush's national security adviser, Condoleezza Rice, the United States is legally responsible for providing humanitarian aid to Iraqis in areas controlled by coalition forces. The United Nations cannot provide humanitarian assistance until security conditions allow the safe return of U.N. staff, Annan told Rice. White House spokesman Ari Fleischer blamed Saddam for slowing the flow of goods by placing mines near Umm Qasr.
Thus far in Operation Iraqi Freedom, Americans said they had taken nearly 4,000 Iraqi prisoners. There was no accurate death toll among Iraqi troops or civilians.
American losses ran to 22 dead and 14 captured or missing. The remains of the first two to die were flown overnight to Dover Air Force Base in Delaware.
Twenty British troops had also died, including two killed Monday by friendly fire.
The U.S. Central Command, which oversees the war, announced the capture of an Iraqi military hospital used as a military staging area. Officials said Marines confiscated more than 200 weapons and stockpiles of ammunition and more than 3,000 chemical suits with masks, as well as Iraqi military uniforms. The Marines also found a T-55 tank on the compound.
Secretary of State State Colin Powell predicted that the coalition eventually will find weapons of mass destruction, saying "there will come a time, when the enemy has been defeated, to make a more thorough search."
Elements of the U.S. 3rd Infantry Division were about 50 miles from Baghdad and hit Republican Guard units defending the Iraqi capital with an all-night artillery barrage.
Thousands of other troops hastened -- as much as the sandstorms would allow -- to join them for the coming battle against Saddam's seat of power.
But some helicopters were grounded by the weather, and combat aircraft taking off from the USS Harry Truman returned a few hours later without dropping bombs on their targets.
Fox News' Kelly Wright, David Lee Miller, Mike Tobin, Carl Cameron, Liza Porteus, Catherine Donaldson-Evans and The Associated Press contributed to this report.