According to BBC, officers were looking for people they allege had vandalized election posters and fled to the property.

A police spokesman said petrol bombs were also found, but Mr Mwamba's party has said they were planted.

There have been growing concerns over political violence in Zambia ahead of next month's general election. BBC reports.

The raid comes just two days after a ban on political campaigning in parts of the country had been lifted.

Mr Mwamba, who was not in the house in Kasama in the country's Northern Province at the time, said his grandchildren were injured during the raid.

"My small grandchildren have been taken to hospital as they have been victims of this barbaric act carried out by the police," he said in a post on his Facebook page.

Mr Mwamba is the running mate of Hakainde Hichilema, the presidential candidate of the United Party for National Development (UPND) party.