Suspects in ‘terror-plot’ held at Dover

The pair – aged 22 and 29 and understood to be of Pakistani heritage – were held at the Port of Dover after arriving from Calais.

A stash of ammunition was seized during the arrests, which later triggered raids on a property in east London, as well as on two vehicles, Scotland Yard said.

British citizens travelling abroad in connection with extremist activities has been a focus for the Security Service for some time, with Syria proving popular with would-be Jihadists.

The former head of MI5 last year warned Britons are increasingly heading to the Middle East for terrorist training in preparation for attacks in the wake of the Arab Spring.

Jonathan Evans, director-general of the Security Service, warned in June parts of the Arab world were becoming a more permissive environment for al-Qaida and Britons were travelling there to ‘’seek training and opportunities for militant activity’’.

The two men were held under the Terrorism Act 2000 by Kent Police on Monday morning on suspicion of “being involved in the commission, preparation or instigation of acts of terrorism”.

They were taken to a London police station where they remain in custody.

The inquiry is being led by the Met’s Counter Terrorism Command.