The firing started suddenly, and Iraqi soldiers and foreign journalists hit the dirt as the sniper bullets whizzed inches overhead. The bullets pinged into date palm trunks and the ground just above a shallow depression that provided the only cover in a field that separated two Iraqi comman posts in this devastated city.

The firing let up after five minutes, and the reporters dashed for the cover of the command post.

Only moments before, an Iraqi major had warned the reporters not to move in front of the windows of his command center, once a university building overlooking a gently curving bridge above the Karun River.

"We don't know what's over on the other side. We are not occupying the other side," he said.

Later, after a tea break with unruffled Iraqi soldiers in the safety of the command post across the open field, the major's point was driven home again.

Iraqi officers kept insisting there was no danger as the group was herded across another 300-yard open field that would take them out of the snipers' range. The first group of five reporters was caught in mid-run by the snipers, sitting in tall buildings across the river. They hit the dirt in a shallow trench.

As the bullets whizzed inches over his head, retired British Army Maj. Gen. Edward Furston, here as a military correspondent for a london newspaper, did a "leopard crawl" for about a hundred yards to safety, followed by the other four correspondents. The remaining reporters, myself included, were pinned down on the other side of the field for 35 minutes, finally escaping in a speedy Iraqi Army jeep that dodged through the bullets.

The only casualty was Niza Samaraie, director general of foreign relations for Iraq's Ministry of Information, who received a slight shrapnel wound in the left hip.

The sniping engagement means little in the large picture of the war, but it illustrates that even though the Iraqi Army controls the city of Khorramshahr, it has advanced no farther in the week since it pushed the last Iranian defenders across the river toward the besieged city of Abadan.

Khorramshahr itself, once Iran's major port, is now a ghost city, populated only by Iraqi soldiers and abandoned dogs, some of them injured in the four weeks of shelling and fighting that preceded the city's capture. Less than a dozen civilians were seen in today's visit, the first here by correspondents since the city was taken.

The sniping also illuminates what the fighting is like up close, as compared to the boastful communiques issued by both sides. It will likely be listed tomorrow by the Iranians as evidence of continued fighting for Khorramshahr although the city now appears lost to Tehran.

[Tehran Radio claimed Thursday that Iranian defenders had gained ground in their battle against the Iraqis in Khorramshahr.]

It also shows that the Iraqi control ends at this side of the bridge, which has now become a no-man's land. Iraq claimed it had taken the bridge in their victory statement last week, but it is clear from today's visit that they only hold one end of it.

Furthermore, the sniper and mortar fire also keeps the Iraqis off balance and lets them know that an assault on Abadan will be costly.

Iraqi officers and reporters, for example were chatting this morning when a heavy mortar shell landed on the roof of the governor's house here, named in the communique as the place where the Iraqi flag was hoisted to signify Khorramshahr's fall.

If Iraq follows the strategy it has used sor far in the war, it will take its time in capturing Abadan, taking as few casualties as possible in the process.

Its troops on this side of the Karun River are three to four miles from the center of the city, which sits on an elongated island, and according to Iraqi officers is completely surrounded and cut off from any supplies.

Yet the Iranians have proved to be tenacious fighters, and are not likely to give up easily. Their only hope of escape appears to be a Dunkirk-like sea rescue off the southern tip of Abadan Island into the Persian Gulf.

That type of operation, however, is not in the character of Iran's Islamic revolutionary government which is preaching the Shiite sect's line that martyrdom in battle for their country and for Islam provides a ticket to paradise. Moreover, any rescue attempt could be subjected to withering fire from shore-based Iraqi artillery.

So far, the Iraqis do not seem to have turned their full artillery power on Abadan, the site of the world's largest oil refinery which is believed to have been heavily damaged in earlier shelling. Shore batteries across the Shatt-al-Arab waterway from here fired only desultory rounds into Abadan last week, and very little shelling could be heard today.

It was clear, however, that the Iraqis are prepared for some type of future assault.

Armored amphibious craft, known in the United States as ducks, were seen on trailer trucks heading in this direction yesterday, and today a number of sections of pontoon bridges were spotted at roadside staging areas.

It is unlikely, though, that the super-cautious Iraqis will mount any amphibious operation until the Iranian forces are softened up some more with artillery.

On the drive here, the Iraqi forces appeared well organized for an assault.

Using the British system, they had clearly marked camps to pick up fuel and other supplies and were black-topping the dirt road running through Iran's oil-rich Khuzestan Desert in preparation for the rainy season next month.

But their supply lines are long, and one illustration of the weakness of the Iranian Air Force is the lack of raids along this major route for men and equipment going to the Khorramshahr front where one or two strafing raids a day could play havoc with Iraq's logistics.

On the way here, Iraqi officers told the four-car caravan of correspondents to expect air raids, but there was none this morning and there were not signs of previous attacks along the route.

At the front, the troops had dug themselves into deep earth bunkers covered with plywood, dirt and sandbags and then camouflaged with tree branches to protect them against mortar attacks.

The port of Khorramshahr itself is not as badly damaged as the city and compared, say, with the condition of the port of Beirut, after the civil war there ended in 1977, it appears ready to operate soon.

Most of the containers used to store cargo are intact and only a few have been opened and looted. The wharfs themselves look normal and Iraqis towed five stranded ships from there to safer berths further up the Shatt. There are still two ships docked here. Iraqi soldiers relax in the port area, a group of them lolling on a dredging ship, fishing in the Shatt.

But the city itself, a once-prosperous bustling place of 300,000 inhabitants, looks completely devastated by the pounding it has taken during the past weeks.There is hardly a pane of glass left and few buildings escaped without some damage from artillery shells. Metal gates were pocked with arms fire.

But the abandoned houses most vividly illustrate the horrors of this war. Outside one in the center of the city lay a child's red and white ball, and inside there was still food on the stove. The house obviously belonged to a prosperous family. It has two television sets and an imported hi-fi. Suitcases were scattered all over, as if the family was trying to decide what to take in a hurried escape and one oriental carpet was rolled up and tied, but left behind.

Other carpets, often the major family wealth in Iran, were left on the floors as was a little girl's doll and a pack of playing cards.

It is impossible to say where the residents went, but there are some indications they tried to flee from here to safety, away from the border. For one thing, there are only a few cars on the streets, meaning that families may have been able to load them up and take off.

In fact, Khorramshahr is no more. The Iraqis have given it its Arabic name, Mohammerah, and Tehran has renamed it Khuninshhr, the City of Blood.