Two men will today appear in court charged with travelling to Syria for terrorism.
Yusuf Sawar and Mohammed Ahmed, from Handsworth in Birmingham, were arrested at Heathrow Airport on Monday after arriving back in the UK on a flight from Turkey.
The men, both 21, will appear at Westminster Magistrates Court in London this morning, West Midlands Police said.
Detectives have said they believe the two men arrested earlier this week travelled to Syria in May last year.
In a statement confirming the arrests, the West Midlands force urged anyone thinking of travelling to Syria to heed warnings issued by the Foreign and Commonwealth Office.
Officers said the case is not connected to the arrest of a 21-year-old from Sheldon, Birmingham, arrested yesterday on suspicion of attending a terrorist training camp in Syria.
West Midlands Police said the man was detained by officers after returning to Gatwick airport on a flight from Istanbul.
Meanwhile, Scotland Yard said it has been given extra time to question two women arrested on suspicion of being involved in the commission, preparation and instigation of acts of terrorism.
O fficers from the Metropolitan Police's Counter Terrorism Command stopped a 26-year-old woman at Heathrow Airport as she was preparing to embark on a flight to Istanbul, Turkey.
She was subsequently arrested and a large quantity of cash was seized, the force said.
A second woman, aged 27, was arrested at an address in north-west London.
Warrants for further detention of the two women were obtained at Westminster Magistrates Court until Thursday, January 23.