DERA ISMAIL KHAN, Pakistan - Pakistan's Taliban have rejected Islamic State leader Abu Bakr al-Baghdadi's claim to be the global leader of all Muslims, the movement said in a statement seen by Reuters on Saturday.The Pakistani Taliban's statement comes after a similar rejection by the Afghan Taliban following pledges of allegiance from low-level commanders of both Islamist movements to the Middle East-based Islamic State (IS).Last year, IS, an al-Qaida offshoot, proclaimed its leader as "caliph" - the head of the state. Al-Baghdadi aspires to establish a global caliphate with himself at its head.The latest statement from the Pakistani Taliban comes amid speculation that the movement's leadership, whose goal is to topple the government of prime minister Nawaz Sharif and set up a sharia state, is actually wary of IS, which is driven by different ambitions that have little to do with South Asia.