The Pakistani government on Tuesday banned a protest march planned by ousted Prime Minister Imran Khan, who is demanding new elections as the country's political and economic crises deepen.

The ban was announced by Interior Minister Rana Sanaullah - in a press statement - hours after a policeman was shot dead during a campaign against Khan's party leaders and supporters across the country.

The interior minister stressed that "no one will be allowed to surround the capital and dictate his demands," adding that the cabinet had approved the ban.

He stated that Khan and his aides described the march as bloody, so it could not be allowed.

"They are coming to Islamabad with evil plans," the Interior Minister said, citing intelligence reports about the march.

Information Minister Maryam Aurangzeb said an official in Khan's party shot and killed the policeman when police went to his house.

The police said that the authorities in Islamabad began to put up roadblocks on the roads leading to important facilities, and police and paramilitary units were deployed extensively.

Khan had urged his supporters to march to Islamabad on Wednesday, warning the government that he would not leave the capital until parliament was dissolved for fresh elections.

He vowed to mobilize tens of thousands.

"Try to stop us if you can," he told reporters, adding that peaceful protest was his right.

Khan defended the firing of the party official, wondering what anyone should do if the police stormed his home.

This official is a retired army officer.

It is noteworthy that in 2014, Khan organized a sit-in for more than 4 months and paralyzed the country.

Thousands mobilized to protest against alleged election fraud in 2013, and his supporters attacked the police and threatened to storm Parliament and the prime minister's home.