KUALA LUMPUR, Malaysia, Aug. 25 (AP) - A prominent Islamic group in the United States has withdrawn its invitation for Malaysian Prime Minister Mahathir Mohamad to speak at its convention. But Mahathir shrugged off the decision by the Islamic Society of North America to retract their request for him address the group next month in Chicago, the national news agency Bernama reported Thursday. ``Maybe I'm thick-skinned,'' Mahathir was quoted as saying during a visit to London. ``I don't feel it was a snub, I feel sorry for them that they are not able to distinguish the truth from propaganda.'' The group withdrew the invitation in protest with the recent prison sentence of jailed politician Anwar Ibrahim. Anwar was sentenced earlier this month to nine years on a conviction on a charge of sodomy. He is also serving an additional six years for corruption. He denies all the charges, saying they were designed to destroy him and end his challenge to Mahathir's nine-year rule. The recent High Court decision also drew widespread condemnation from Western nations and international human rights groups. They have expressed concern over the manner in which the trial was conducted and the harshness of the verdict. Mahathir, however, said he felt sorry for those who became supporters of Anwar's cause because they were unable to distinguish right from wrong. ``It is clear that they only listen to one side and do not want to listen to the other side of the story,'' he was quoted as saying by Bernama.