South African police say they have arrested a man accused of threatening to unleash biological weapons on Britain and the United States.
In a statement, police said a six-month terror investigation by South African, British and US officials culminated with the man's arrest on Saturday morning in north-western South Africa.
Police spokeswoman Sally de Beer said his name will not be released until a Johannesburg court appearance on Monday.
While police say they took his threats sent by mail and email seriously, they have not yet found evidence he was capable of carrying them out.
Ms De Beer said police are still searching the man's home and other sites.
Police say the suspect threatened to carry out the threats unless he was given 4 million dollars (£2.5 million).
