Merapi, which means "Mountain of Fire", has been belching potentially deadly heat clouds from its depths for a week and spewing red-hot lava trails down its sides, prompting authorities to declare a top alert and evacuate thousands.
But the royally appointed guardian Marijan, aged in his 70s, is unconvinced that the mountain poses an immediate threat and has refused to budge from his hamlet here, bordering uninhabited forest a few kilometres from the peak.
He has even trudged closer to the peak, completing two nights of meditation at the sacred spot of Kendit before leading this rite near midnight on Thursday, an auspicious time according to ancient Javanese beliefs.
Marijan reads out a brief Islamic prayer -- the vast majority of Indonesia's 220 million people are Muslims but here many combine this with blends of ancient Hindu-Buddhist beliefs -- before leading the march.
Although the procession, which begins with six men in traditional attire and six women, should be a serene