Calls to withdraw Italian troops from Afghanistan were growing on Thursday night after six soldiers were killed by a suicide car bomber who rammed a Nato convoy in Kabul. Italians were shocked by the worst casualties the country has suffered since the start of the Afghan war. Umberto Bossi, a key partner in Silvio Berlusconis centre-right coalition, added to pressure on the prime minister by saying all Italian forces should be home in Italy by Christmas. Mr Berlusconi, however, reiterated that Italy would not take any unilateral action after the attack and the countrys contribution to a very difficult situation would continue. Italy has 2,800 troops deployed in Afghanistan. The bulk of these forces are concentrated in the western Herat province, which borders Iran. Franco Frattini, the foreign minister, said: It is right at this difficult moment that we remain close to the Afghans and not forget that our presence in that country enhances their and our security. The attack looks certain to fuel debate within Italy about the campaign. The centre-right party of Silvio Berlusconi, the prime minister, appears to back the governments strategy but at least one coalition member the Northern League, led by Umberto Bossi has called for Italys to be withdrawn from Afghanistan. Antonio di Pietro, the leader of a small liberal party, said on his blog: While we insist on staying in Afghanistan we no longer know the reasons why we went there. Italian disquiet at an increasingly unpopular war echoes a debate in Germany this month, when a German commander called in an air strike that killed 30 Afghan civilians and 69 insurgents, according to a presidential investigation. Ten Afghan civilians were killed and 55 wounded in Thursdays blast, which deals a fresh blow to a western mission locked in a growing confrontation with President Hamid Karzai over disputed elections. Like other elections of the world . . . there were problems and sensitivities in the Afghanistan elections but it has not been to the extent which the media speak of, Mr Karzai told his first news conference since the August 20 polls. Mr Karzais confidence in the votes integrity set him at odds with European Union observers who said on Wednesday that more than a million ballots cast for the president, over a third of his tally, were suspect. A UN-backed Electoral Complaints Commission has ordered a recount that could overturn preliminary results that hand Mr Karzai 54 per cent of the vote enough to avoid a run-off with Abdullah Abdullah, his main challenger. Mr Abdullah said the recount must be respected even if it created short-term uncertainty. How can we surrender to fraud to decide our destiny? This is the wrong foundation for our country and it will only strengthen the insurgents, he said. . The mounting insurgency and political uncertainty over the polls have sharpened a dilemma faced by Barack Obama, US president, over whether to send in more troops . Mr Obama sought to bolster support for the war from a sceptical public on Wednesday by sending Congress a list of benchmarks to measure success in battling Afghan insurgents and hunting militants in Pakistan. Washington said the attack on Italian troops highlighted the need for the US and its allies to remain united in Afghanistan. This vicious act of terrorism reinforces the need for the US and allies, in partnership with the people of Afghanistan, to continue our critical work, the state department said. We are united in our commitment to defeat the extremist elements, whose intention is to destroy the freedom and dignity to which all people are entitled. European diplomats they expect any call for more troops for the war effort to also be directed at them but argue that in many countries it would be politically impossible for some countries to send more forces to what has become an unpopular war. General Stanley McChrystal, the Obama administrations handpicked commander for Afghanistan, is expected to ask for more troops to establish a presence in parts of the country now dominated by the Taliban. Admiral Mike Mullen, the head of the US joint chiefs of staff, also said this week that the US would probably need more troops. But in a sign of the depths of the dilemma confronting him as he chooses between heeding the advice of his generals and responding to mounting concern among Congressional Democrats and US public opinion as a whole, President Barack Obama said this week that no decision on sending more resources was imminent. (The Times)