Britain has increased security at ports and border points after the deadly attack in Paris, though British officials say there is no specific new threat to the country.

Prime Minister David Cameron's office said Thursday the national threat level remained at "severe," the second-highest rung on a five-point scale. That means intelligence officials believe an attack is highly likely.

Home Secretary Theresa May -- who chaired a meeting of the government's COBRA security committee -- said police and border guards had "intensified checks on passengers, on vehicles and on goods coming from France and other parts of Europe."

There is also more visible border security at Paris' Gare du Nord, where British border officials check passengers heading to London on the Eurostar trains.