French authorities said early Tuesday that there is a police operation underway at France's Gare du Nord station, the terminus of Eurostar trains from London. Research and Intervention Brigade (BRI), the elite police force also arrived to the scene.

A single tweet from Paris' police service announcing the operation gives very little detail, saying "Police intervenes into the scene for security checks."

Video and photos posted to social media appear to show a sizeable police operation at the busy station.

France has been in state of emergency for over a year after Daesh terrorist group organized attacks in the capital and claiming lives.

The latest attack was when an attacker with an automatic weapon opened fire on police on Paristarget="_blank"'>