Story highlights Official: A large-scale search involving police, firefighters is underway

The avalanche hit a group of 10 hikers and their guide, the official says

Paris (CNN) Three people are dead and about seven others remain unaccounted for after an avalanche Wednesday in the French Alps, an official in the Hautes-Alpes prosecutor's office said.

One person was evacuated to a hospital in Grenoble, France, in "extremely serious condition," according to the official, who spoke on behalf of Hautes-Alpes prosecutor Raphael Balland.

The avalanche happened around 3 p.m. (9 a.m. ET) around France's Ecrins National Park near the village of Pelvoux, which is about 40 kilometers (25 miles) west of the Italian border and 120 kilometers north of where Germanwings Flight 9525 went down last week.

It struck a group of about 10 hikers and a guide, the prosecutor's office said.

A large-scale search is underway for those still missing.

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