Fear and suspicion inside the kill zone

Phillip - he does not want his surname published - is a civil engineer on a six-month contract in Iraq with a US construction company, which he has already extended by three months. Back home, he would normally commute into London from his home in Kent.

"I would take a train at 7.30am from Sevenoaks. There were always delays, you could never sit down. And the routine was so tedious," he said. "Coming to Iraq seemed a good idea at the time. I am 37 years old and I am earning 40 per cent more than I was getting in the UK, and living expenses are negligible.

"But then you think about what happened to poor Ken Bigley ... It's very sad, but also very scary. My wife is extremely worried, she wants me to go home as soon as possible."

Iraq is now effectively one big killing ground, and the expatriate community, including 2,100 British nationals in Baghdad, are already living in a state of siege. The waves of diplomats, businessmen, aid workers and journalists who arrived at the end of the war have largely evaporated. A small fraction remain behind, either counting the days to their return home, or bringing that date forward.

More than 150 foreigners have been taken hostage in Iraq, and 23 of them killed, with many of the murders filmed. Unsurprisingly, the effects on reconstruction have been devastating, with many projects vastly behind schedule. There are other threats beside abduction. While the US forces and their Iraqi allies attack insurgents in Samarra, Babil and Fallujah, the enemy has brought the war home to the Iraqi capital. Not a day goes by without a suicide car-bombing or a mortar or rocket attack, often in the city centre.

Even staying "locked down" in heavily guarded hotels or houses in barricaded compounds is no guarantee of safety. A few hours after Mr Bigley's murder in Latifiya, a short drive south-west of Baghdad, on Thursday, rockets were slamming into the Ishtar Sheraton in the heart of the city.

The hotel, and the Palestine opposite, are homes to a large number of contractors, security personnel and American media organisations including CNN, Fox News and The Washington Post. They are guarded by Iraqi troops and American armoured cars, but that has not stopped nine attacks since the war. Further down in the same complex are the BBC, Reuters and The New York Times. It takes 15 minutes to walk from the car park outside the fortress to their houses. The journalists have been told not to go outside the walls unless absolutely necessary. Last week a pick-up truck full of explosives, hidden by a load of dates, drove into a convoy of private security guards leaving the complex. Three people were killed.

Most other foreigners stay in the Green Zone, a 10 sq km "sanitised" area where the US and British embassies and the offices of the Iraqi interim government are based. It is bristling with guns and security; even with the right credentials one has to undergo repeated searches.

It is a slice of middle America with joggers along the tree-lined avenues, a mall, a bazaar, cafés and restaurants catering to Western tastes. But one cannot keep Baghdad out. On average, mortars are lobbed in from the streets outside three times a day. Three days ago a bomb was discovered outside the Green Zone café, one of the most popular attractions for off-duty soldiers. There are dangers of kidnapping even here, and the foreign residents, especially women, are advised not to go out by themselves after dark.

TOLL SINCE KEN BIGLEY'S CAPTURE

Eugene Armstrong, 20 September

"Jack", as the 52-year-old was known to friends, had worked on construction projects in Angola and Thailand before travelling to Baghdad. In a memorial service in Michigan last month, friends remembered a "multi-talented" man full of enthusiasm.

Jack Hensley, 21 September

Killed the day before he turned 49, he had travelled to Iraq, leaving a wife and 13-year-old daughter in the US. The civil engineer was working on water, electricity and schools programmes.

Akar Besir, 21 September

A Turkish driver working for the American military, Mr Besir was taken hostage around 18 September. His body was found in the northern city of Mosul.

Anwar Wali, 2 October

The 44-year-old was kidnapped at the end of August from his Baghdad home and killed by militants who accused him of spying. Mr Wali was an Italian citizen of Iraqi origin. The Italian government described him as a businessman.

Yalmaz Dabja, 2 October

Mr Dabja, 33, was executed at the same time as Mr Wali. A video released by his killers shows him being forced to kneel in front of a ditch before being shot. He was also accused of spying.