Three men appeared in court in London on Thursday to face accusations of traveling to Pakistan for terrorism training, UK media reported.
A woman charged with having terrorist material also appeared at Westminster Magistrates Court, the Press Association news agency reported.
The men were charged Wednesday night with preparing for acts of terrorism, London's Metropolitan Police said.
They are also accused of traveling abroad to commit acts of terrorism and "advising and counselling the commission of terrorism acts by providing information about travel to Pakistan, terrorism training and operational security while there," police said.
Police identified them as Richard Dart, 29, Imran Mahmood, 21, and Jahangir Alom, 26.
The woman, Ruksana Begum, 22, was charged at the same time with having a digital memory card containing documents useful to a terrorist, police said.
The four did not enter a plea during Thursday's proceedings.
Police said the offenses occurred between July 25, 2010, and July 6, 2012.
One of the suspects lives in the east London area, where the Olympic Games get under way this month, but police have said the arrests were not connected with the Olympics.
All four have been remanded into custody and will next appear in court on July 31, according to the Press Association.