AMMAN, JORDAN, FEB. 6 -- Iraq claimed today that an allied raid killed 150 civilians in a city in the south -- the highest toll from one raid reported by the government so far -- and official reports and witness accounts told of heavy bombing in and around Baghdad and numerous other cities.

After weeks of playing down the casualties and the human cost of the war, Iraq today painted its 21-day toll in harsh terms of civilian destruction and accused President Bush and the U.S.-led coalition force of attempting to "expel Iraq from the 20th century."

In a move that appeared to have little practical effect but apparently was intended to show the intensity of its anger toward the allies, Baghdad also announced it was severing diplomatic relations with the United States and other countries in the multinational force -- Britain, France, Italy, Egypt and Saudi Arabia -- most of whom already had pulled their diplomats out.

Iraq accused the United States and its allies of attacking residential districts during nearly 300 air raids Tuesday night and today and charged that 150 civilians, including 35 children, were killed in Nassariyah, 200 miles southeast of Baghdad on the Tigris River. That is the highest single casualty toll reported by Iraq since the war began.

Despite Iraq's reports of high civilian casualties, however, travelers from Nassariyah arriving in Baghdad told the Associated Press that the allied bombs had smashed military and industrial targets during the intensive bombardment. U.S. officials have insisted that the war is being waged only against military targets and that civilians are not deliberately being bombed.

Peter Arnett, of Cable News Network, who visited Nassariyah, a city of 1 million people about 70 miles north of Basra and the Kuwaiti border, said Iraqi authorities showed him a bombed bridge over the Euphrates River, which bisects Nassariyah.

Authorities told reporters that 46 civilians who were on the bridge when allied bombers hit it Monday were killed. The Iraqi government is "saying now that bridges are really civilian targets, not strategic" ones, Arnett said.

As he drove back to Baghdad, Arnett said, there were "heavy air strikes on both sides of the road."

In Baghdad today, allied air strikes knocked out a key bridge across the Tigris River, and bombing raids continued against the port of Basra and other southern cities.

Reports from Iran said the reverberations of huge explosions were heard and felt from across the border in Iraq. The Iranian National News Agency, IRNA, reporting from the border city of Khorramshahr, said buildings trembled 30 miles away as a result of huge explosions caused by missiles and bombs falling on southern Iraqi cities.

IRNA quoted refugees fleeing the war as saying that "in Basra, most bridges, mosques, schools and residential areas have been destroyed."

"Those who have fled say no one is immune anywhere in Iraq from the fire of the U.S.-led forces," IRNA said.

"The roar of U.S.-led coalition planes is heard attacking Basra and other Iraqi southern cities every five minutes but the Iraqi defense system is apparently silent," IRNA reported. It said, however, that allied planes raiding some other Iraqi cities were drawing "very active" anti-aircraft fire.

The Iraqi government newspaper Al-Thawra said 349 people had been killed in Basra since the war began, AP reported.

IRNA said 217 more refugees from Iraq -- mostly foreigners who had been working there -- entered Iran overnight, bringing the total since the war started to about 2,700 foreign refugees and 55 Iraqis. It quoted refugees as saying gasoline was not being sold to people in cities that are targets of allied raids in order to prevent residents from fleeing, Reuter said.

In Baghdad, authorities said the allies carried out 281 air raids and missile attacks overnight and today and said Iraq had shot down six allied planes and missiles, the Associated Press reported. U.S. military officials in Saudi Arabia said there had been no allied aircraft losses.

According to Reuter correspondent Bernd Debusmann in Baghdad, an air strike, apparently by a cruise missile, flung a 50-yard section of the Jumhouriya Bridge, over the Tigris River, into the water, leaving two huge gaps at the northern side with dangling slabs of cement and twisted metal.

The powerful explosion that ripped through the bridge littered part of Baghdad's business district with glass fragments from blown-out windows, Debusmann reported.

Today's destruction of the bridge, one of eight across the river in the capital, increased psychological pressure on a population already strained by a lack of electricity and by serious water shortages resulting from the cutoff of power used to operate pumps and purification plants.

One of the few diplomats left in Baghdad was quoted by Reuter as estimating civilian casualties running into thousands, although, before today, Iraq had put the official total of civilian fatalities at 428.

While Iraq had been largely close-mouthed and low-key in reporting casualties in the first weeks of the war, its official statements now appear to be stressing civilian losses and the human toll.

The forces led by Bush "raided our residential neighborhoods" to "murder women, children and the elderly, {but} the scoundrels did not achieve any of their objectives," Baghdad Radio quoted a military spokesman as saying. It said the Iraqi people would "pursue" Bush "and his accomplices . . . for this crime, even if they leave office and disappear into oblivion."

Refugees fleeing Iraq said Baghdad residents are coping by collecting rainwater in plastic pails and cooking on small fires in their backyards to save on bottled gas and kerosene.

One Vietnamese refugee at the Azraq camp in Jordan said prices for basic commodities are soaring, with the cost of 1 kilogram of rice {2.2 pounds} jumping to about $15. Previously, a kilogram of rice sold for about 60 cents.

IRNA reported today that "according to those who have fled Iraq in recent days and sought asylum in Iran, a sack of flour is sold at 800 dinars {$2,560 at the official rate} on the free market." It did not say how large the sack was.

Reuter reported from the United Nations:

A U.N. team is planning to deliver emergency medical supplies to Baghdad next week for the benefit of children and mothers, a U.N. spokesman announced. This would be the first medical shipment sent to Iraq through the United Nations since the war began Jan. 17.

However U.N. officials have been reluctant to send a team while the bombing continues, and it was not known what arrangements might now be made to ensure the safety of the medical mission and its supplies.