Zambian opposition leader has been charged with treason for obstructing president Edgar Lungu's motorcade on a main road in one of the country's provinces at the weekend.
Hakainde Hichilema's convoy declined to pull over to allow the presidential convoy to pass. Both were on their way to a traditional ceremony.
"It has been established that the opposition leader disobeyed police orders to give way to the Presidential motorcade on Limulunga road in an attempt to put the life of the Republican President in danger,” said Kakoma Kanganja, the inspector general of police, in Lusaka.
"I wish to reiterate that the actions by the opposition leader were unreasonable, reckless and criminal.
"We shall ensure that all those that would want to cause unnecessary anarchy are arrested and prosecuted."
Police surrounded Mr Hichilema’s house outside Lusaka early on Tuesday, firing tear gas before he was taken into custody.
Mr Hichilema, head of the United Party for National Development, does not recognise Mr Lungu as president and has refused to accept the result of a presidential election last August.
"We gave ourselves up to the police after a long ordeal of enduring teargas the whole night," Mr Hichilema said in a message on his Facebook page.
"Shortly before being handcuffed, we were very clear in our mind and told the police officers that we were giving ourselves up for the sake of the country, We were giving ourselves up for the sake of the suffering masses."
Hichilema, head of the United Party for National Development, has challenged the results of the election, saying the result vote was rigged in favour of Mr Lungu's Patriotic Front party.
Treason is punishable in Zambia with a minimum jail term of 15 years and a maximum sentence of death.