Kabul blast kills three ahead of Afghan state-building conference

A lone suicide bomber managed to slip through a tight-security cordon in Kabul on foot yesterday and detonate his explosives in a market area near the US embassy, killing three people the day before the world's top diplomats began arriving in the city for the biggest international meeting in Afghanistan since the 1970s.

Afghan and Nato forces promised to do everything they could to prevent a terrorist spectacular tomorrow when delegates from 60 nations – including the Foreign Secretary William Hague, the US Secretary of State Hillary Clinton and the UN secretary general Ban ki-Moon – meet to thrash out ways of handing more control of the reconstruction and development effort to the Afghan government.

"We are 100 per cent prepared but this doesn't mean everything will go exactly to plan. We will try to do our best and we will also rely on the support of God," said Zemarai Bashary, a spokesman for the interior ministry.

The news comes as the Ministry of Defence named three British servicemen who died in other incidents in Afghanistan on Friday and Saturday. Last night tributes were paid to marine Jonathan Crookes, 26, and Sergeant David Monkhouse, 35, who died in explosions , and airman Kinikki Griffiths, 20, who died in a road accident.

In what appeared to be a declaration of intent from the Taliban militants to sabotage the conference, yesterday's bomber eluded the thousands of extra police and blast barriers. His device shattered windows, wrecked cars and scattered body parts in the explosion. Among the three victims was a child.

Mark Sedwill, Nato's top civilian representative in Afghanistan, told reporters: "We have to prepare ourselves for the fact that the insurgents are going to seek to disrupt this [conference]".

Although the conference is expected to last just a few hours, that was more than enough time for militants to disrupt a 1,600-member convention last month that President Hamid Karzai had called to discuss a rapprochement with the Taliban. While none of the delegates were harmed on that occasion, Mr Karzai apparently felt the rocket attacks and a gun battle were enough of an affront to accept the resignations of his interior minister and spy chief.

Afghan and international forces claim to have already arrested around 30 militants involved in a number of plots to attack tomorrow's event.

Although the emphasis of meeting is supposed to be state building, the resulting communiqués are expected to also contain an agreement by international forces to start handing over security to the Afghan government, with peaceful provinces like Bamiyan and Panjshir likely to switch control first.

President Karzai is due to announce that by 2014 Afghan security forces will start taking the lead in military operations around the country. This has been "spun" by the British government as representing the time UK troops will be home. In reality, what this will mean is that, like last week's Operation Omid Do, Afghan troops will play a key role in planning missions but will be accompanied by Western forces. The finer details of withdrawal timeframes are only likely to emerge at a summit in Lisbon later this year once Nato members have had time to agree on them.

According to a report by Oxfam, the point of tomorrow's conference is hard to fathom for the ordinary population. "Many Afghans are tired of conferences where ministers from all over the world talk about the future of their country with nothing changing on the ground," Ashley Jackson, the charity's head of advocacy in Afghanistan, said.

"[It] creates the illusion of action but it is actually what happens after the conference that matters most. We're deeply concerned that far too many troop-contributing countries are looking for ways to get their troops out rather than looking at the root causes of the conflict and poverty."