Authorities have detained Pakistani opposition party leader Shah Mehmood Qureshi, Pakistan Tehreek-e-Insaf spokesman Zulfi Bukhari said on Saturday.
Earlier, Qureshi told reporters former prime minister Imran Khan's party would challenge any delay in the country's election, which is to be held within 90 days of parliament being dissolved, which in this case means early November.
Qureshi is the vice chairman of Pakistan Tehreek-e-Insaf, led by former premier Khan, who is currently in jail. Khan has denied wrongdoing.