Emperor Akihito began the controversial final ceremony Thursday in his accession to the Chrysanthemum Throne, a communion with the mythical sun goddess from whom legend says the imperial line descended.

The Shinto rite has been performed by most of Japan's monarchs since at least the 7th century but is criticized by many Japanese as violating the separation of church and state because of its overtly religious nature.More than a dozen of Japan's 47 governors turned down invitations to Thursday's rite, many because of the church-state controversy.

Police were out in force Thursday because of the threat of violence by ultra-leftist radicals who want to abolish the monarchy.

Police said radicals were believed responsible for a fire that destroyed a Shinto shrine in northern Japan Thursday. On Wednesday, anti-monarchy radicals shoveled human waste from the back of a truck near the Imperial Palace.

Akihito, 56, is the first Japanese emperor to be enthroned not as a god-king but as a symbol of his people's sovereignty. But that has not diminished the pomp and ceremony of his coronation.

As many as 26,000 police were assigned to security in Tokyo alone Thursday, and Prime Minister Toshiki Kaifu and nearly 900 Japanese dignitaries were expected to attend the final ceremony, scheduled to begin this evening.

Unlike Akihito's formal state enthronement ceremony Nov. 12 that was viewed by foreign dignitaries representing 158 countries, no foreigners were invited to the communion, which is to end before dawn Friday.