The crackdown brought a swift end to the protests that have gripped Islamabad, Pakistan’s capital, this week ever since thousands of people gathered in the city to demand the release of Imran Khan, the former prime minister. Mr. Khan has been in prison since last August on charges that his party claims are politically motivated.

Over 10,000 protesters surged into city, defying a lockdown and a ban on public gatherings to skirmish with 20,000 security forces enlisted to turn them back.