Suicide bomber attacks UN Baghdad headquarters

The United Nations. Again. Only last week, I'd stood at the little desk in the morning sunlight where the UN's Iraqi guards checked visitors to what's left of the headquarters after the previous suicide bomber came calling.

And the rumble of sound that moved across Baghdad yesterday morning came from those very same few square yards. A car bomb, detonated by the driver, so the Americans would say two hours later, as the Iraqi UN guard checked his vehicle.

But why would a car bomber - a suicide bomber if that is what he was - drive up to a checkpoint where the security men were bound to discover his bomb? "He tried to enter the UN compound but he wasn't going to make it," a US officer called Kirley told us in the hot morning sunshine.

His men were protecting the wrecked UN headquarters, devastated in last month's suicide murder of 22 UN officials. "He couldn't make it, so he decided to kill civilians."

But when I asked if perhaps the driver had been unaware of the bomb in his car, that maybe someone else had planted the bomb and that it was destined for a different target - maybe an innocent driver had decided to pull up at the UN on his way to another location - the officer said he didn't know. Yet why not the UN? Wasn't Kofi Annan, the secretary general, opening a conference on the "war on terror" in the United States yesterday? Wouldn't yet another bomb at the UN finally knock the stuffing out of any army that wanted to travel to Iraq under a UN flag to pull the American army out of the mire? America's only chance of exchanging its own soldiers for an international force therefore took another body blow yesterday. One Iraqi driver - or car bomber - dead and one Iraqi UN security guard dead.

Was he the man who gave me my UN visitors' pass last week? It's the kind of question we all ask every time a bomb goes off in Baghdad. An Apache helicopter circled the smouldering wreckage of the sedan car as a truck-load of American troops turned up with sandbags.

Always sandbags. Walls of sand and concrete and earth are now climbing around Baghdad, outside police stations, outside US bases; a concrete wall 20ft high and miles in length now snakes along the western side of the Tigris river through Baghdad to protect the American proconsul Paul Bremer and his staff. Approach any American facility and you will be met by a tank barrel and barbed wire. And we all ask: "Who's next?" It felt safer on the streets of Baghdad yesterday, even reporting the bombing of the UN car park, than it did in one's own hotel.

A couple of weeks ago, the Baghdad Hotel - where CIA agents reportedly live - was apparently due for attack. Snipers fired at the security guards and, so the story went, a car bomber was waiting to drive to the building. But the guards fought back and the car never appeared.

Then there's the story - apparently true - that someone planted three bombs underneath one of the biggest river bridges in Baghdad, allegedly the Jamhouriya bridge; three bombs, each made of mortar shells, which would have brought the bridge down when an American tank crossed the river. And of course, you can imagine the pictures on CNN if the Americans had to haul an Abrams tank out of the Tigris.

On Sunday night, there was shooting near my hotel, bursts of fire that lasted, on and off, for 10 minutes. In the morning, no one could say what happened. Was a local trying to protect his property? Was someone firing at the US military compound, which is quite close - rather too close, in my opinion - to the back of my hotel, a former Saddam family villa that is now occupied by US line troops? When he took over, Mr Bremer promised better security in 60 days. His 60 days are up. And the results of his promise definitely merit "Non satis".