Deadly unrest has continued in Pakistan following the arrest of former prime minister Imran Khan earlier this week. Massive protests erupted across the country as his supporters called for his release.

The government has warned that any violent demonstrators will face severe penalties.

Pakistani Prime Minister, Shehbaz Sharif said in a televised speech, "The perpetrators who take the law into their own hands will be dealt with, with an iron hand. They'll be punished according to the law and the constitution."

Khan was arrested in a land fraud case on Tuesday, and was reportedly charged with a separate case the day after. Local media say that he allegedly sold state gifts during his four years in power.

Some demonstrations have escalated, with protestors destroying police vehicles and setting fire to a radio station.

At least four people were killed and over 80 others were wounded in the northwestern city of Peshawar on Wednesday, as crowds clashed with security forces. A hospital in the area says many casualties were caused by gunfire.

Local media reported that authorities in the capital Islamabad and some provinces had called in military troops to restore order.