LONDON (Reuters) - British police have arrested a 41-year-old Frenchman after "what appears to be a firearm" was discovered at Gatwick airport following the Paris attacks.

The airport's North terminal was evacuated and flights cancelled earlier following a security alert. The terminal has reopened.

"The man is being interviewed as we try to determine the circumstances of the incident, but at this time it is too early to say what his intentions, if any, were," Detective Superintendent Nick May was quoted as saying by BBC. "However, given the events in Paris on Friday evening, there is heightened awareness around any such incident and it is best that we treat the matter in all seriousness."

The evacuation came amid heightened security after attacks in Paris left more than 120 people dead on Friday and Britain's Prime Minister David Cameron convened a meeting of his government's emergency response committee.

Britain's terrorism threat level stands at "severe", the second highest category which means a militant attack is considered highly likely.

Gatwick airport is the country's second busiest airport and is situated about 30 miles south of London.