Frontline troops expect Iraq to fire chemical weapons soon. Yesterday it was just Scuds. Jack Fairweather reports from the demilitarised zone on the Iraqi border.
Chemical and biological sirens echoed throughout the desert yesterday as Iraqi forces responded to a pre-emptive missile strike on Baghdad with a salvo of Scud missiles and artillery fire.
At half-hour intervals the artillery rounds came, shaking the ground lightly with their impact.
From a vantage point in sight of the Iraqi border, artillery rounds could at times be seen landing in and around allied forces, although no casualties have been reported.
Along with six Scud missiles fired at Kuwait so far yesterday, the retaliatory fire is an indication that, far from laying down their arms and surrendering, Iraqi forces in southern Iraq intend to fight.
"Scud, Scud, Scud," the call went up at one of the camps now forward-deployed inside the demilitarised zone.
At the site where one of the missiles landed in north-western Kuwait near American positions, a large crater had been cordoned off.
Troops, moving in protective clothing and gas masks and assembled by their vehicles in defensive position, appeared tense although the two missiles that landed in Kuwait yesterday have been described by one military official as "conventionally armed".
That did not stop one soldier briefly fumbling with his NBC suit during one of four chemical and biological attack alerts, leading to him being doused in anti-germ warfare powder.
"We know they're coming," said one British soldier a few kilometres from the border, "We know he's going to start firing his chemical weapons at us soon."
His commanding officer, displaying remarkable presence of mind as shells fell nearby, said: "We're not worried. This is all part of the game-plan.
"We're letting Saddam throw everything he's got at us. Saddam's showing the world just why we have to enforce regime change," he said.
With the approach of evening yesterday allied forces returned fire, although so far the strategy has been to let Iraqi artillery positions reveal themselves before the aerial bombardment begins.
The length of that campaign will, it is thought, be shorter than the expected two to three days, with troops in the demilitarised zone told to be ready to move "at an hour's notice".
British armoured regiments stationed further south are expected to begin moving tonight.
All along the long earthen rampart that marks the outer edge of the demilitarised zone breaches have been made in preparation for their arrival.
Inside the zone itself advance reconnaissance units have already spotted enemy units a short distance away on the Iraqi side of the border.
"It doesn't look like they'll be laying down their arms to me," said one soldier.
"We had hoped for the defections to have begun by now, but instead things are really hotting up," he added.
Although the intensity of the Iraqi shelling has led to some units being given orders to move back from the most frontline positions, driving through the demilitarised zone yesterday it was clear that troops bedded down for the night were more than prepared.
Behind every bush and derelict farmhouse seemed to lurk a tank or armoured personnel carrier under camouflage.
Many of the buildings chosen for cover were the bombed-out walls of farms destroyed during the first Gulf War.
Everywhere the ghostly debris of 12 years ago could be seen: rolls of rusting barbed wire and mortar craters slowly filling with sand.
More recent remains have been left by the departing Kuwaiti army, which until Tuesday had been patrolling the border. British troops have reported finding portable shower units, pyjamas and a 24-piece dinner set.
"They obviously left in a hurry," said one soldier.
Yesterday only three Kuwaiti soldiers manned a border zone checkpoint and were obviously nervous at the sound of the shelling, training their weapons on all who approached.
The bombardment also seemed to have finally persuaded the Kuwaitis living in farms near the border that it was time to leave, as they began fleeing south to Kuwait City.
In their wake they left a bizarre scene: their Bangldeshi workers have been told to stay behind and keep working on the farms. They could be seen tending herds of camels and sheep yesterday not far from the border.
One man watering his tomatoes had stuffed his ears with cotton wool to keep out the sound of the shelling. Another had lost his herd of sheep as they scattered in disarray at the shells struck.
Meanwhile at a petrol station in sight of Safwan hill from which Iraqi artillery pieces have been firing all day it was still possible to get a tank of petrol.
As he stood at his pump, the sight of the flowing petrol had inspired one Kuwaiti man with an altogether different plan from his compatriots speeding south.
"I will drive into the demilitarised zone tonight," he said, "and I hope to see the fireworks."
As darkness fell yesterday it would seem his wish had come true, as the night sky was illuminated by the light of detonating artillery shells.