British police said Thursday they had arrested two more people over alleged involvement in terrorism in Syria following the discovery of ammunition at the port of Dover.
A man aged 27 and a woman aged 26 were detained at a house in Essex on Wednesday following a search and are still being questioned, the Metropolitan Police said.
They were held “on suspicion of being involved in the commission, preparation and instigation of acts of terrorism”, it said.
Their arrests came after two men aged 29 and 22, both British citizens, were held on Monday in Dover after arriving from Calais in France and a quantity of ammunition was seized.
Police were carrying out searches at premises in London and in Lancashire, it said.
British police have in recent months arrested a number of people on suspicion of travelling to Syria to fight with Islamist rebel groups opposed to President Bashar al-Assad.