A plane at Damascus airport
A plane at Damascus airportReuters

British police arrested two people at London's Heathrow Airport as part of an investigation into travel to Syria for alleged terror activity.

The suspects, a man and a woman, both 26, were arrested Tuesday night after arriving on a flight from Egypt, London's Metropolitan Police said in a statement.

Police did not clarify whether the suspects were thought to be returning from or heading to Syria.

The statement said that officers were searching two homes in east London as part of the investigation.

The statement said that the suspects were arrested on suspicion of the "commission, preparation or instigation of acts of terrorism." The statement did not reveal the suspects' names, nationalities, or any other identifying information, Fox News reported.

They were taken to a central London police station and remain in custody.

The British Foreign Office did not comment directly on the arrests but said the "deteriorating security situation (in Syria) leaves dangerous space for foreign fighters."

"We are concerned about reports of extremist groups operating in Syria and we take very seriously any claims that British nationals are among foreign fighters there," the foreign office said, according to CNN.