The US has offered to help Uzbekistan probe the attacks which have killed at least 42 people in the last three days. American Secretary of State Colin Powell made the offer in a telephone call to his Uzbek counterpart. Uzbekistan says 23 people died when suspected militants blew themselves up during a gun battle with special forces in the capital, Tashkent, on Tuesday. On Sunday and Monday, 19 people were killed and 26 injured in bombs in Tashkent and the city of Bukhara. The US and Uzbekistan have been close allies since the 11 September attacks, after which the Uzbek government made its airspace and military facilities available to US forces, facilitating the operation to remove the Taleban in neighbouring Afghanistan. Uzbekistan has since become an important strategic outpost for the US. State Department spokesman Richard Boucher said that while the two countries may have co-operated in the war on terrorism, Uzbekistan must introduce democratic reforms: \"More democracy is the best antidote to terror,\" he said. No-one has claimed responsibility for the attacks, the bloodiest seen in the former Soviet republic for years. Uzbek officials have suggested one group, Hizb ut-Tahrir, could be to blame. But the group, which has its headquarters in London, has denied any involvement, saying it \"does not engage in terrorism, violence or armed struggle\". Another group under suspicion is the home-grown Islamic Movement of Uzbekistan (IMU). The group\'s leader Tahir Yuldashev is accused of orchestrating the series of deadly bomb attacks in Tashkent in 1999. However, Shahida Tulaganova of the BBC\'s Central Asia Service says that the group, which fought alongside the Taleban during the Afghan conflict is now in tatters, with many of its leaders being held by the US in Guantanamo Bay, Cuba. (BBC)