(Adds quotes, details) SHARM EL-SHEIKH, Egypt, March 28 (Reuters) - A Saudi-led military operation has targeted a base where Iranian-backed Houthi fighters had set up long-range missiles and pointed them towards the southern Yemeni city of Aden and neighouring countries, a Yemeni official said on Saturday. Iran denies allegations made by some Yemeni and Western officials that it is providing money and training to the Shi'ite Muslim Houthis, whose rapid territorial advances triggered an Arab military campaign against them.