At least 1,500 supporters of cricketer-turned-politician Imran Khan have been arrested by Pakistani police in a nationwide crackdown ahead of a planned opposition rally this week.

The arrests followed weekend clashes between Khan supporters and riot police, as demonstrators took to the streets to call on Prime Minister Nawaz Sherif to resign.

Riot police attempted to disperse crowds using tear gas and batons, and on Sunday, violence erupted again near Mr Khan's suburban home and in several areas on the outskirts of the capital Islamabad.

On Monday, a Pakistani court barred Khan supporters from demonstrating on the streets of the capital, restricting the rally to the confines of a city park.

This followed a two-month ban enforced last week on street rallies in the capital.

Police also placed shipping containers on key highways leading to Islamabad in order to prevent Mr Khan's party convoys from reaching the capital from across the country.

Mr Sharif has come under fire after his family members were named as holders of offshore bank accounts in leaked financial documents from the Panamanian law firm Mossack Fonseca.

Government spokesman Zaeem Qadri said police have carried out raids based on information about planned violence.