(South Korean shaman Lee Soon-ae performs prayers during a shipboard ceremony intended to exorcise the demons that threaten fishermen and bring good luck to everybody on board, off Incheon, in the west of Seoul June 24, 2012. REUTERS/Choi Dae-woong)

Colourful flags snapped in the sea breeze as more than a dozen Korean shamans, dressed in bright colours, danced and chanted prayers in front of a huge cow’s head stuck to a trident.

The ceremony on a ship was designed to exorcise demons that threaten fishermen and bring good luck to everybody on board. The presence of several hundred spectators underlined how the ages-old trance rituals were going strong again, having been shunned as recently as 30 years ago.

“People are trying to understand more, learn more, and see more. They are very interested in this,” said Kim Keum-hwa, one of South Korea’s most famous shamans, who led the ceremony.

Though an ancient practice, Korean shamanism – in which singing and dancing are used in trance rituals addressed to specific gods, often to get an answer to specific questions – had long been suppressed in Asia’s second most Christian nation.