A later blast, caused by magma hitting snow, injured at least 10 people, news outlets reported.
One of the world's most active volcanoes, Mount Etna spewed lava up into the sky in the early hours of Thursday for the third time this year after it began erupting in late February.
Sicily's Mount Etna volcano unleashed an explosion Thursday, hurling molten rocks and steam that rained down on tourists, journalists and a scientist who scrambled to escape the barrage.
Six people remained in nearby hospitals Thursday afternoon recovering from injuries.
Morelle said a volcanologist with them on the peak described the incident as the most risky in his 30-year career.
In this video, the eruption is shown on thermal cameras, which were located around 3km from the volcano's mouth.
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Morelle said all those involved in the eruption were "okay" and had been brought of the mountain safely by an "excellent rescue team".
Volcanologist Boris Behncke, part of the expedition, also received minor injuries to his head during what he described as a "violent explosion".
There is no confirmation as to how the serious their injuries are.
She added that a "huge explosion" caused rocks and steam to be pelted at the group. The volcano previously had an active eruption rate of 1.7 years until 2001, when activity became more frequent.
The injured were hit by the lava, boiling rocks and steam erupting from the volcano, but none of them are in critical condition.