Thousands of mourners gathered Friday in and near a Qatari mosque to bid farewell for the slain leader of Palestinian Islamist Hamas, Ismail Haniyeh, after he was killed in Tehran earlier this week, Qatari state television said. The funeral service, which was also attended by Qatari and Arab officials, began at noon (0900 GMT) with a prayer at the Imam Abdul Wahhab Mosque, the largest state mosque in Qatar. According to Hamas, Haniyeh’s body would then be buried in a cemetery in the city of Lusail, north of Doha. Qatari state television, which is broadcasting live, reported the highest securit…