© Patrick Tradgardh/Bank Sweden
Reindeer herders in the region were taking around 3,000 animals across the river, a route that has been safely crossed on previous occasions.
"The ice suddenly gave way and hundreds of reindeer fell into the water," said Bertil Kielatis, chairman of the Sirges Sami village in Jokkmokk.
"Now we are working to recover the animals that have drowned," he added.
Sirges is Sweden's largest Sami village with around 300 members and 90 herders.
The incident means a substantial financial loss for the herders and disaster for the local community.
"It's a tragedy in many ways," Kielatis added. "Not only for the reindeer that suffered but for the herders who were helpless to save their animals."
The reindeer were lead by herders who drove snow-mobiles and were assisted by a helicopter.
Kielatis added there was nothing unusual about the route or the way the herding was carried out.
"This is how we usually work nowadays when leading a large herd up or down from the mountains," he said.
We all get by with the 'usual' way of doing things until forced by the unforeseen to do otherwise.