Two missing coal miners have been found alive but injured after a tremor struck a mine in southern Poland, a mining company said.
Rescue crews are still trying to reach five other missing miners, officials said.
The rescue operation was launched at 11:25am local time after a tremor occurred at the Zofiowka coal mine, said Katarzyna Jablonska-Bajer of the Jastrzebie Coal Company.
There has never been such a powerful tremor at the mineKatarzyna Jablonska-Bajer
The mine is located in the southern town of Jastrzebie-Zdroj near Poland’s border with the Czech Republic.
She said four miners were brought to the surface, but contact was lost with seven others who were 900 metres (2,950 feet) underground, preparing a new corridor for extraction work.
At first, high methane levels in the mine prevented rescuers from trying to reach the site – but after four hours they began to head there, she said.
Poland’s State Mining Authority said the tremor had a magnitude of 3.4 on the Richter scale, while the European Mediterranean Seismological Centre pegged it at 4.3 magnitude.
TVN24 said the tremor was also felt on the surface and shook some houses.
“There has never been such a powerful tremor at the mine,” she said.