Pakistan’s former prime minister Imran Khan has been arrested at the High Court in the capital, Islamabad.
Mr Khan was appearing in court on charges of corruption, which he says are politically motivated.
Footage showed dozens of paramilitary forces in armoured vehicles detaining the 70-year-old after he entered the court compound, and then driving him away.
Unrest broke out in several cities following his arrest, with protesters blocking key roads.
Mr Khan was ousted as PM in April last year and has been campaigning for early elections since then.
General elections are due to be held later this year.
Speaking to the BBC’s Newshour, Mr Khan’s spokesman, Raoof Hasan, said he expected “the worst” and that the arrest could plunge the country “into chaos and anarchy”.
“We’re facing multiple crises. There is an economic crisis, there is a political crisis, there is a cost of livelihood crisis and consequently, this occasion will be a catharsis for them to step out and I fear a fair amount of violence is going to be back,” he said.
A member of Mr Khan’s legal team, Raja Mateen, said undue force had been used against him.
“Mr Khan went into the biometric office for the biometrics. The rangers went there, they broke the windows, they hit Mr Khan on the head with a baton,” said Mr Mateen.
“And they dragged Mr Khan from there. They didn’t care that this person had come to court while injured.”
Mr Khan’s Pakistan Tehreek-e-Insaf (PTI) party has called on its supporters to protest. In the hours since he was detained, violence has been reported from a number of cities including Lahore, Karachi and Peshawar.
On the streets of Islamabad, hundreds of protesters blocked one of the main highways in and out of the capital.
People pulled down street signs and parts of overpasses, lit fires and threw stones. During the hour or so that the BBC was there, no police or authorities were visible.
