Rescuers are searching for a man who fell into a crack in the ground that opened up after a volcano erupted in Iceland last month.
The man was working to fill crevasses formed by earthquakes and volcanic activity in the town of Grindavik, which had been evacuated in November, according to local media.
Hundreds of people have been looking for him since Wednesday but had to stop shortly before midnight on Thursday due to a rockfall.
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“At midnight, we had to stop the search because we could not guarantee the safety of those who were working down in the crevasse,” Ulfar Ludviksson, the police chief in South Iceland, told local media.
“There was a rockfall at the top.”
Reports said work was being done to widen the opening of the narrow crevasse, which could only accommodate two people at a time.
Earlier, Mr Ludviksson told Icelandic national broadcaster RUV on Thursday that conditions were “very difficult and demanding”.
“It’s deep down. This runs tens of metres down to the bottom. There is water far below this work area where rescuers are working,” he said.
“There are two men who go down in a basket and stay down for about 10 minutes. Then they come up and the other two take over.”
Intense earthquake activity in Iceland culminated in a spectacular eruption in December, as molten rock spewed from fissures in the ground in the Reykjanes peninsula after a crack around two miles long emerged and grew rapidly.