CNN reports: A massive manhunt for two brothers wanted in the Charlie Hebdo magazine firing  focused on northern France's Picardy region, where sources close to the investigation said a police helicopter might have spotted the suspects.

Authorities believe that Cherif Kouachi, 32, and Said Kouachi, 34, entered a wooded area on foot, the sources told CNN. Now investigators are using helicopters equipped with night vision tools to try to find them, the sources said.

Earlier Thursday, a police helicopter glimpsed what investigators believed to be the fugitives in the same area, near Crepy-en-Valois, France.

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