DUSHANBE (Reuters) - Al-Qaeda aims to infiltrate Central Asia to train militants and turn the ex-Soviet region into a zone of unrest, a US envoy said on Saturday. US Special Representative for Afghanistan and Pakistan Richard Holbrooke is on a blitz tour of the five 'stans of Central Asia. I think the real threat in this region is less from the Taliban but from Al-Qaeda, which trains international terrorists, he said on a visit to Tajikistan. This is an issue of common concern to the US and to all the countries of this region. And by all the countries I definitely include Pakistan and China and India. Stability in the vast resource-rich region sprawling between China, Russia and Afghanistan is crucial to the West as it lies on a new supply route for NATO-led operations in Afghanistan. The regions main home-grown extremist group, the Islamic Movement of Uzbekistan (IMU), wants to topple Central Asias secular post-Soviet leaders and establish strict Islamic rule. Its fighters were forced out of the region after the end of a 1990s civil war in Tajikistan into Pakistans lawless tribal areas, where its leadership is believed to have established close contacts with Al-Qaeda, security analysts say. Holbrooke is also visiting Kyrgyzstan, Uzbekistan, Turkmenistan and Kazakhstan during his first trip to Central Asia in his current capacity. In Uzbekistan, the regions most populous and ethnically diverse nation, President Islam Karimov told Holbrooke he was eager to work closer with the United States over Afghanistan. The leader of our nation ... expressed Uzbekistans firm determination to further develop US-Uzbek relations in a constructive way in light of efforts to bring lasting peace and stability to Afghanistan, the official UZA news agency said. Uzbekistan is now part of the new NATO supply route and Western nations rarely criticise its rights record. Last year the EU angered international human rights groups by lifting sanctions it imposed on Uzbekistan after a violent crackdown by Uzbek troops on protesters in 2005.