A Frenchman with gun was arrested at Gatwick airport, reported AFP.
Earlier, the North Terminal of Gatwick Airport was evacuated after a suspect package was recovered from the area, reports said.
"Due to an incident - the North Terminal has been evacuated as a precautionary measure. Extra staff on-site looking after passenger welfare," read the official tweet by Gatwick Airport Twitter handle.
Unconfirmed reports on social media suggested that a man carrying a gun (or grenade) was arrested by the Sussex police.
Gatwick airport, which is the UK's second busiest airport, is located about 48km south of Central London.
The development comes after security was heightened in the UK, following a series of terror attacks in Paris, which has claimed 127 lives so far.
Check out tweets below:
#gatwick_airport North Terminal evacuation in the rain pic.twitter.com/8aeeP8VWJF
— Tim Unwin (@TimUnwin) November 14, 2015
#gatwick_airport North Terminal evacuation pic.twitter.com/Qe2ecFR03h
— Tim Unwin (@TimUnwin) November 14, 2015
Due to an incident - the North Terminal has been evacuated as a precautionary measure. Extra staff on-site looking after passenger welfare
— Gatwick Airport LGW (@Gatwick_Airport) November 14, 2015