British police arrested a man and a woman at London’s Heathrow Airport as part of an investigation into travel to Syria for alleged terror activity.

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

The statement did not say whether the pair was headed to Syria or had returned from there. Authorities did not release their names.

The two were taken to a central London police station and authorities began searches of two homes in east London as part of the investigation, police said.

The British Foreign Office did not want to 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.

(Source: CNN)