| Last updated
The tourists had been in south-east Iceland admiring the Breiðamerkurjökull glacier on the edge of Vatnajökull National Park, when a large section of the ice broke away - something known as 'calving'.
In the video footage, which was shared by Icelandic tour company Háfjall, people can be seen running away from the shoreline to safety as a large wave moves towards them.
Stephan Matler, a mountain guide and the owner of Háfjall, said thankfully no one was hurt.
"I could see all of them start to move out of harm's way and their guides also ready to jump into action if necessary, so I kept recording but with a watchful eye on people's movements," Mantler said, CNN reports.
Mantler explained that the area is only accessible with a trained mountaineer, and everyone is briefed about what to do in the case of a calving before they embark on a trip.
"While calvings are fairly frequent at this time of the year, this was an extraordinarily large event and much closer to the shore than usual, which is why it was such a close call," said Mantler.
"In the end, most importantly, nobody got hurt or even wet."
One person commented on the video to say they'd been near the location just three years ago, adding: "I wish we could have witnessed some calving there or in Svinafelsjokul."
But the tour company replied to say it's often a case of 'luck'.
Háfjal replied: "It's not as common on Svínafellsjökull or any of the other glacier lakes; Jökulsárlón is connected to the ocean so there are tides coming in and out and stressing the glacier even more.
"It also depends on the time of year, weather, and always requires patience - or luck."
Someone else commented to say they were one of the tourists in the video, writing: "Before the glacier collapse happened, our tour guide told us when we heard 'Boom! Boom! Boom!', we have to run run run.
"Thanks the tour guide for saving our lives."
Another person said: "Those people are super lucky - hard to believe some were so far out!"
A fourth added: "Holy crap! Good thing they ran like ants."
Yup, while it's pretty cool to see the footage of what happened, I'm very grateful not to have been experiencing it in real life...
Chosen for YouChosen for You
Most Read StoriesMost Read