British police say they have charged a 23-year-old man with the preparation of terrorist acts.

Hampshire police said Sunday that Mustakim Jaman, who was arrested after police executed search warrants on Oct. 14, is scheduled to appear in court Monday.

Jaman is from Portsmouth on the English coast 120 kilometers (75 miles) southwest of London. The city is home to a handful of young men who have left England to join Islamic State fighters in Syria.

Police have warned that an increasing number of British Muslims are joining the conflict there and may return to Britain after receiving terrorism training.

The official threat level in Britain is set at "severe," indicating that an attack is highly likely.