Saviour Chishimba, president of the United People’s Party, was picked up at a privately-owned television station in the capital, Lusaka, where he had gone to record an interview.

He was charged in connection with comments he made about the president during a press conference last month.Mr Chishimba has made no comment about the charges.He is now the second opposition leader in Zambia to currently be in detention.

Hakainde Hichilema, who heads the country's largest opposition party, was arrested in April and is facing treason charges.