The incident took place in Devka river near Veraval, the district headquarters.
"A group from Geeta Nagar in Veraval had gone for Lord Ganesh's idol immersion. Five persons from the group carrying the idol entered the river, but they lost balance and drowned," said P P Vanja, in-charge of Gir-Somnath Police Control Room.
"Four of them were between 18 and 22 years, while the fifth one was aged around 45," he said, adding their bodies have been fished out and sent for post-mortem.