PRAYAGRAJ, India (AP) -- Tens of thousands of naked Hindu ascetics and millions of pilgrims took dips in freezing water at the confluence of sacred rivers in northern India on Tuesday, in the first of a series of major baths in the Maha Kumbh festival, the largest religious congregation on Earth. Holding tridents, swords, spears and small two-headed drums, ash-smeared Hindu holy men marched and rode chariots at sunrise toward the confluence of the Ganges, Yamuna and mythical Saraswati rivers in the northern city of Prayagraj. The men, with matted dreadlocks and crowns of marigolds, chanted religious slogans praising Hindu deity Lord Shiva on the way to the bathing site in a large procession with singing, drumming and blowing of horns. The Maha Kumbh festival -- held every 12 years -- started Monday, with more than 15 million pilgrims bathing in the holy rivers, according to officials. Over about the next six weeks, the festival is expected to draw more than 400 million people.