ISLAMABAD (AFP) - Pakistan's media watchdog has banned television channels from broadcasting live addresses by former prime minister Imran Khan, ahead of his rally on Sunday (Aug 21).

Since being ousted from power in a no-confidence vote in April, the former cricket star has staged a series of popular anti-government protests.

The ban, effective immediately, was issued late on Saturday night - the same day Mr Khan held a rally in the capital Islamabad in which he criticised police officials and the judiciary over the arrest of one of his party's leaders.

In a notice to television channels seen by AFP, the Pakistan Electronic Media Regulatory Authority said Mr Khan was levelling "baseless allegations and spreading hate speech".

"His provocative statements against state institutions and officers... is likely to disturb public peace and tranquility," it added.

The former premier is set to hold another rally tonight in the city of Rawalpindi, neighbouring Islamabad.

Mr Khan swept into power in 2018, thanks to an electorate weary of the dynastic politics of the country's two major parties, with the popular former sports star promising to sweep away decades of entrenched corruption and cronyism.

He remains highly popular among the country's youth and his speeches draw top ratings on television, with highlights trending on Pakistan's social media.

Saturday night's protest followed the arrest of a senior leader from Mr Khan's Pakistan Tehreek-e-Insaf (PTI) party, who the authorities alleged had made anti-military remarks on a TV channel that was subsequently suspended.

Criticising the military - which has ruled Pakistan for roughly half its 75-year history - is considered a red line.

A PTI senior official, Mr Asad Umar, lambasted the media regulatory body's move to ban Mr Khan's speeches.

"Banning Imran Khan's speeches telecast is another attempt to find an administrative solution to a political problem," Mr Umar told AFP.

He added that his party will challenge the ban in court.