DOHA (Reuters) - Al-Jazeera television said one of its cameramen was killed on Tuesday in a U.S. air raid on Baghdad which set ablaze the network's downtown office. "We regret to inform you that our cameraman and correspondent Tarek Ayoub was killed this morning during the U.S. missile strike on our Baghdad office," the Qatar-based channel said in a statement read out during its news bulletin. The network, one of the most widely watched in the Arab world, had earlier reported that Ayoub was seriously wounded after a missile hit its Baghdad office. A second Jazeera correspondent was slightly...