Allies suffer on road to Baghdad

Captured US soldiers paraded on TV; RAF jet shot down by 'friendly fire'; Heavy fighting in Basra

Allied forces encountered some of the stiffest resistance of the war so far yesterday, when their charge towards Baghdad was met by a furious guerrilla-style ambush near the town of Nasiriyah that claimed significant casualties and allowed the Iraqis to take their first prisoners.

American Marines launching their northward thrust over the Euphrates were apparently tricked by a column of Iraqi soldiers indicating they wished to surrender. They turned out to be units of the elite Saddam Fedayeen, and opened fire as the Americans approached.

A supply convoy was also ambushed in the attack, which Lieutenant General John Abizaid, a US spokesman, described as "the sharpest engagement of the war thus far".

At least four Marines were reported killed and dozens injured. US officials also said 12 soldiers were missing, apparently captured. Five of them later appeared in video footage aired on both Iraqi television and the Al-Jazeera satellite network, along with four other US soldiers lying dead.

The Pentagon immediately denounced the treatment of the prisoners as a violation of the Geneva Conventions, and President George Bush urged Iraqis to treat the soldiers humanely.

The British Government asked the media not to show the images and Major General Peter Wall, the senior British officer at Central Command, Qatar, called them "disgusting".

The four-day-old invasion became bogged down on several fronts, with fierce fighting also reported near Najaf, 100 miles south of Baghdad, as well as in several towns in the south, especially around Basra. US military sources claimed 70 Iraqi dead near Najaf, while the Iraqis said 77 of its civilians had been killed in Basra.

US forces were last night reported to have discovered a chemical weapons factory and a cache of chemicals near Najaf. However, there was no independent verification by advancing US troops of the apparent find, which was first reported by the Jerusalem Post.

In Baghdad, suffering its fourth day of heavy bombardment, thousands of Iraqis lined the banks of the Tigris to see Iraqi security men hunting for two US pilots claimed to have parachuted into the river after their aircraft was shot down. Iraqi officials said they had shot down several aircraft over the capital ­ a claim denied by the Pentagon.

Despite continuing upbeat assessments of the war's progress, US political and military leaders appeared to be taken aback by the latest developments. "This is just the beginning of a tough fight," a notably drawn President Bush cautioned on his return to the White House from Camp David.

Richard Myers, chairman of the US Joint Chiefs of Staff, added: "This is going to get a lot harder. Anybody that thinks this is going to be quick and easy is wrong." In London, the War Cabinet was urged to be patient. Tony Blair's spokesman said: "The coalition forces are making real progress and, accidents notwithstanding, events are unfolding very much to plan."

The US strategy appears to be to advance on Baghdad in a complicated pincer movement, with columns of tanks and artillery units advancing through the desert on several tracks at once. Although many rank-and-file Iraqi units appear to be offering light resistance or surrendering, pockets of Republican Guard troops are periodically springing surprises on the Allies and attempting to lure them into street-by-street fighting in towns and cities.

Central Command insisted the battle of Nasiriyah was over and won. It also said, not for the first time, that the southern port of Umm Qasr was safely in Allied hands, and hundreds of Iraqi soldiers were surrendering outside Basra. Reports from journalists on the ground, however, suggested there were still pockets of resistance as well as deep resentment, concealed by initial welcoming smiles.

The war effort was further frustrated by "friendly fire" accidents, which were also the bane of the Gulf War in 1991. A US Patriot missile shot down a British Tornado jet over northern Kuwait as it returned from a bombing run in what US commanders described as a "tragedy". The two crew members were confirmed dead last night and General Tommy Franks, the US commander running the war, said he would launch an investigation.

ITN also issued a statement saying it believed its correspondent Terry Lloyd had been killed by American "friendly fire" outside Basra. Mr Lloyd's body had been identified in a morgue in Basra, ITN said. The fate of his Belgian cameraman and Lebanese translator was still unknown.

The British and US governments both continued to claim that the Iraqi leadership was crumbling last night but they also tacitly conceded that Saddam Hussein had almost certainly survived the initial cruise missile attack on a Baghdad villa that started the war in the early hours of Thursday ­ despite rumours the Iraqi leader may have been killed or mortally wounded.

Intelligence reports suggested President Saddam left the area in an ambulance, the Foreign Office minister Mike O'Brien told BBC radio yesterday.