By Nick Miles
BBC News, Johannesburg
Zimbabwean police have arrested another 7,000 people as part of a countrywide campaign against illegal traders.
On Wednesday, the police burnt an informal market in a Harare suburb
State radio said the arrests were made in the town of Gweru in the centre of the country.
It brings the number of people arrested in Zimbabwe over the last week to more than 17,000.
Zimbabwe state radio said the people were arrested for hoarding scarce goods like maize, dealing in foreign currency and gold panning.
The town of Gweru lies in a rich mining belt and thousands of unemployed people have moved there in recent years to eke out a living looking for gold.
Some of the people arrested have paid fines; others have been taken to court.
There have been large numbers of police on the streets of Gweru and 1,000 extra officers are patrolling the capital, Harare, to prevent any violent reaction to the arrests.
On Wednesday, when the police burnt an informal market in the Harare suburb of Glen View, street traders threw stones at the police and then looted several shops.
Despite the tensions, the police say the arrests will continue.
The government says it wants to stop the damage the black market is doing to the economy, namely stoking an already high rate of inflation.
But more than 80% of the people in Zimbabwe are jobless and for the majority of the population, the informal economy is the only way of making a living.