Pakistani police Wednesday arrested and charged a prominent journalist investigating claims of casualties during a government crackdown on opposition protesters in the capital, Islamabad, earlier this week, drawing strong condemnation from media freedom advocates.

A Pakistani journalist investigating claims of casualties in a protest march demanding the release of jailed ex-prime minister Imran Khan was picked up off the street on Wednesday night and charged with terrorism,

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.