A public communication center that was hit during an  airstrike in Baghdad, Thursday March 27, is seen from a bus during a press tour in this picture taken Friday, March 28,  2003. Intense U.S. bombing on the Iraqi capital continued  Friday, aimed at disrupting communications between  Saddam Hussein's leadership and his military.  (AP Photo/Jerome Delay)

The biggest bombs dropped on Baghdad so far - two 4,700-pound "bunker busters" - struck a communications tower Friday in an intense U.S. bombardment. In the south, British officers said Iraqi fighters defending the besieged city of Basra fired on hundreds of civilians trying to flee.  The British, who have encircled Basra, said their troops were trying to rescue and aid civilians wounded by the mortar and machine-gun fire from paramilitaries loyal to Saddam Hussein. A young woman badly wounded by shrapnel was driven to safety in a British vehicle, according to reporters near the scene.  "Here perhaps are the first pieces of evidence of Iraqi people trying to break free... and clearly the militia don't want that," said Col. Chris Vernon, a British spokesman.

At Umm Qasr, near Basra, the first ship arrived at the allied-controlled port with relief supplies for Iraqi civilians. The Sir Galahad, a British supply ship, carried 300 tons of water, sugar, beans, and flour. 

Fighting raged across the south - including a battle at a cement plant in which a U.S. Marine was killed - and a showdown in central Iraq over Baghdad was clearly drawing closer. With a new front opened by paratroopers in the north, U.S. forces are poised to move on the capital from multiple directions.  Wary of engaging the better-armed allies in open desert warfare, Saddam's government has been goading them to send ground troops into the city.  "The enemy must come inside Baghdad, and that will be its grave," said Defense Minister Sultan Hasidim Ahem. "We feel that this war must be prolonged so the enemy pays a high price."  U.S. Defense Secretary Donald H. Rumsfeld, briefing congressional committees in Washington, suggested American troops might lay siege to Baghdad rather than invade, in hopes its citizens would rebel against the government.

The sun sets behind a large cloud of black smoke  from burning oil fires ringing the city of Baghdad as  a defense against missiles Friday, March 28 2003.  The biggest bombs dropped on Baghdad so far _  two 4,700-pound (2,115-kilogram) ``bunker busters'' _ struck a communications tower Friday in an  intense U.S. bombardment. (AP Photo/Karim)

The Army's senior ground commander in Iraq, Lt. Gen. William S. Wallace of V Corps, told reporters of The New York Times and Washington Post on Thursday that unexpected tactics by Iraqi fighters and stretched supply lines were slowing down the campaign. "The enemy we're fighting is different from the one we'd war-gamed against," the papers quoted Wallace as saying during a visit to the 101st Airborne Division headquarters in central Iraq. 

Brig. Gen. Vincent Brooks, at the daily briefing at U.S. Central Command in Qatar, insisted U.S. war planners had not underestimated Iraqi fighting capabilities, but said unexpected developments were inevitable in any war. He accused the Iraqis of using "terrorist death squads" who changed in and out of civilian clothes. 

Brooks also said U.S. and British troops were expanding TV and radio broadcasts in Iraq, including Baghdad, aimed at reassuring civilians and encouraging soldiers to capitulate. 

In one of the areas where resistance has been unexpectedly tough, U.S. Marines and Iraqi forces exchanged tank and artillery fire Friday in the strategic southern city of An Nasiriyah. Several buildings, including the power plant, were ablaze. 

An Nasiriyah, on the Euphrates River near a junction of roads that lead from Kuwait to Baghdad, has been the scene of some of the fiercest fighting of the war. 

Near the south-central city of Ad Diwaniyah, one Marine was killed and another injured in fighting with Iraqi irregulars at a cement plant in what one Marine officer, Lt. Col. B.P. McCoy, described as "blue-collar warfare." Two other Marines were killed when a vehicle ran them over while they slept. 

In Baghdad, smoke drifted across the city - from fires started by authorities to conceal targets as well as from sites struck overnight in one of the heaviest allied air assaults of the war. 

U.S. officials said bombs and Tomahawk missiles struck several communications and command-and-control facilities in the city, including the tower hit by two "bunker-busters" dropped from a B-2 bomber. One of Baghdad's main telephone exchanges - a seven-story building - was hit and gutted, but phones were working Friday in many parts of the city. 

Iraqi Information Minister Mohammed Saeed al Sahhaf told reporters that 75 civilians had been killed and 290 wounded in U.S. and British bombardments overnight, including seven deaths in Baghdad. He also said Iraqi forces destroyed or damaged several allied vehicles and killed four soldiers in an attack on a convoy near Najaf, less than 100 miles south of Baghdad. 

Sahhaf rejected allied contentions that Iraq planned to use chemical weapons - speculation that arose after advancing forces found chemical weapons protective suits and gas masks left behind by retreating soldiers. Sahhaf said having such equipment is standard for any army. 

Iraqi state TV broadcast a sermon by cleric Abdel-Ghafour Al-Quisi; a Kalashnikov rifle was seen resting against the pulpit. "May God install terror in the hearts of our enemies," he said. 

Nine days into the war, Pentagon officials said close to 90,000 U.S. troops were in Iraq, with 100,000 to 120,000 more on the way. Some will be deployed in northern Iraq, joining 1,000 airborne troops who parachuted in Wednesday night to secure an airfield. 

A paramount U.S. objective in the north is to seize the valuable oil fields near the city of Kirkuk, about 80 miles from the airdrop site. 

Russian President Vladimir Putin described the war Friday as a threat to global stability and the most serious crisis since the end of the Cold War. He called for an end to the fighting, and resumption of U.N. efforts to forge a political settlement.