The arrest of former Pakistani Prime Minister Imran Khan on Tuesday sparked mass protests across the country. Some have turned violent, and two people have been killed.
Police say more than 170 Khan supporters and police officers were injured.
Khan was reportedly detained while at a court in Islamabad for a separate case. Investigators say Khan was arrested on suspicion of corruption.
Tensions remain high in the capital, Islamabad, on Wednesday, with heavy security. Local media reported that internet connections and access to social media have been disrupted across the country.
Khan's lawyer insists there was "absolutely no case" against him.
The lawyer, Babar Awan, said: "The arrest of Imran Khan is state abduction. It is not an arrest. It is state abduction."
Khan's arrest comes at a time when Pakistan is in the midst of an economic crisis.
Khan remains popular among people who aren't satisfied with current Prime Minister Shehbaz Sharif, including the younger generation and low-income Pakistanis.
Khan was forced to step down in April last year after losing a no-confidence vote. He has since been at odds with Sharif.