The event, which marks the end of the Christmas season, is popular among tourists.
It traditionally involves around 1,000 male participants known as guizers, who wear Viking dress and divide into squads to parade through the town.
The procession is led by the Guizer Jarl, or chief guizer, and culminates in the participants using their flaming torches to set ablaze a replica Viking longship.
The modern event, first held in 1881, is known for its festive parties that often involve traditional Shetland dancing and copious alcohol consumption.
Rural "Up Helly Aa" processions on Shetland, which lies in the middle of the North Sea some 400 miles (640 kilometers) from Edinburgh, started allowing women to take part in 2015.
But the town of Lerwick's committee initially stood firm against allowing female participants to get involved in celebrating the island's Norse heritage.
This year -- despite the lifting of the gender restrictions -- there are no women in the main Jarl squad which leads the procession. However, women are taking part in other historic costumed squads involved in the event.
Festival organizers said it was not necessarily a surprise that there were no female participants for the 2023 Jarl Squad, since it was formed back in 2021, before the lifting of gender restrictions was announced in June 2022.
"It is expected that females participating in the Jarl Squad will evolve in the coming years, but we'll see females participating in some of the other 46 squads from the 2023 festival," the "Up Helly Aa" committee said ahead of the event.
The torch-lit processions and longboat burning are an echo of pagan Norse rituals -- the Shetland and neighboring Orkney Islands were ruled by the Norse for about 500 years until they became part of Scotland in 1468.
© 2023 AFP
