British police have arrested a Canadian man on suspicion of being a member of a terrorist group.

The Metropolitan Police in London, England say counterterrorism detectives arrested a 28-year-old Canadian national at Heathrow Airport shortly after noon on Monday.

They say the man had just arrived on a flight from Canada and that the investigation related to the arrest hours earlier of a man in east London.

Both men stand accused of membership in a proscribed terrorism organization, which could carry a sentence of up to 14 years in prison if charges are laid.

The men are currently being held without a warrant, which can be done for a maximum of 48 hours under the U.K. Terrorism Act.

In an email, Metropolitan Police say they are not naming the terrorist group as the investigation is ongoing. Police said that they would only confirm the identity of the people they arrested if they are charged with an offence.