Among them are Emmanuel Mwamba, a senior official of the Patriotic Front (PF), the main opposition party, who was detained for a Facebook post urging people to protest against the government.

He is accused of inciting hatred and violence by the police. Another PF leader, Given Lubinda, a former Justice Minister, was arrested for allegedly holding a diplomatic passport illegally.

The police also charged Raphael Nakachinda, a PF member of parliament, and Fred M'membe, the leader of the Socialist Party, with espionage.

They claim that the two opposition figures participated in a documentary by Zimbabwe's state broadcaster that was critical of Zambia's elections in August.

The opposition leaders have denied any wrongdoing and said they are being persecuted for their political views.

The arrests have sparked condemnation from civil society groups, the Catholic church and the Law Association of Zambia, who have warned that democracy is under threat in Zambia.

The government has dismissed the criticism and said it is upholding the rule of law.

--ChannelAfrica/Reuters--