British police have arrested four people in the past week as part of an investigation into suspected terrorism in Syria.
A 27-year-old man and a 26-year-old woman were detained on Wednesday in Essex, east of London, the Metropolitan Police said in a statement Thursday. On Monday, two men aged 29 and 22 who had just entered the the country at the southern English port of Dover were arrested, officials said.
The arrests were made in relation to what police called "the commission, preparation or instigation of acts of terrorism" in Syria.
The 29 and 22-year-old were arrested under terror laws and taken to a London police station where they remain in custody. Some ammunition was also recovered, police said.
Their arrest prompted the investigation and eventual detentions in Essex on Wednesday.
In addition to the arrests, police said they were carrying out search warrants at a building in East London and an address in Lancashire, a county in North West England.
"No arrests have been made at either of these addresses. The searches are ongoing and we are unable to provide more details at this stage," police said.
Police did not discuss any further details of the case.