LONDON - British police said on Thursday that two men arrested at the southern port of Dover this week are suspected of being involved in terrorism in Syria.

The men, aged 29 and 22 - both British citizens - were stopped by police as they arrived by ferry from Calais on Monday. They were arrested under the Terrorism Act.

A quantity of ammunition also was seized, police said without elaborating.

“The arrests relate to suspected terrorism in Syria,” they added in a statement. No further details were immediately available.

Searches were going on at addresses in east London and in the northern county of Lancashire on Thursday, the statement said. A third man and a woman also have been detained.