General John Abizaid, America´s senior military commander in the Middle East, has admitted that suicide bombers are likely to penetrate polling stations during today´s Iraqi elections, despite unprecedented security measures.

Even as President George W Bush predicted that "the courage of the Iraqi people will allow the vote to take place", his top officer for the region warned: "Undoubtedly, insurgents are going to attack polling sites with suicide belts wrapped around them."

Gen Abizaid told an American newspaper that in the four Iraqi provinces dominated by Sunni Muslims, where the insurgency is strongest, the election-day battle "will be tough and it will be difficult and it will be bloody." Yesterday, insurgents seeking to disrupt Iraq´s first free elections for 51 years launched a string of attacks that claimed at least 18 lives.

In one incident, a suicide bomber blew himself up outside a joint US- Iraqi security centre in the town of Khanaqin, north-east of Baghdad, killing three Iraqi soldiers and five civilians.

Mr Bush declared in his weekly radio address: "In the face of this intimidation, the Iraqi people are standing firm. Tomorrow´s elections will happen because of their courage and determination. All throughout Iraq, these friends of freedom understand the stakes."

Ayad Allawi, Iraq´s interim prime minister, urged his fellow countrymen to defy the insurgents "trying to break us and to break our world". He pleaded: "They should take part because this is the future in the making, and people have to take their fate in their own hands and decide for themselves what kind of future they want."

Not all Iraq´s politicians were optimistic. The country´s president, Ghazi al-Yawar, a Sunni Arab in the interim government, told reporters: "What we hope is that most Iraqis will take part in the election but we know that the majority will not because of the security situation." Later he amended his comments, saying that he believed that two-thirds of the country´s 14 million eligible voters would take part.

More than 400 Iraqis have been killed in the past month, almost all as the result of attacks launched by insurgents opposed to the continuing presence of the US-led military forces that toppled Saddam Hussein from power 21 months ago.

Another senior US military officer in Baghdad predicted that the insurgency - which has been fuelled by small groups of hardened Arab fighters from neighbouring countries - would last at least a decade and could not be defeated by American troops alone.

The officer told The Telegraph: "Iraqis are the ones who will have to defeat the insurgency, not multi-national forces. It is not necessarily a growing insurgency but it is a resilient one." (© Copyright of Telegraph Group Limited 2004. 01/30/05)