Although police confirmed the death of five panners last week, Mutare residents believe the figure could be higher.
Of the five killed, two were shot dead by police; the other three died in collapsed tunnels.
Assistant Commissioner Edward Mbewe confirmed the deaths and added that a police officer sustained serious head injuries in the incident.
Police are facing stiff resistance from the illegal panners, who have used iron bars against officers.
Mbewe maintained that the police were not fighting a losing battle, but also admitted that some officers were themselves involved in illegal mining. The police, he said, had recommended to a board to fire the officers, as they were bringing the name of the force into disrepute.
The panners enter the diamond fields in organised syndicates after paying officers for passages. Soldiers have also been implicated in the illegal trade, and there have been clashes as criminals fight for position.
Some people have made their fortunes in Chiadzwa communal lands and the surrounding areas, as traders come from as far as South Africa to buy the gems.
There is a hell of a lot happening here and those heavily connected to Zanu (PF) bigwigs are making fortunes, said a source in the area.
Manicaland provincial spokesman Inspector Brian Makomeke revealed to The Zimbabwean that it would be a while before the syndicates were rounded up.
We carried out an operation to weed out the rogue elements at Chiadzwa but, from the look of things, it is going to take a long time before the situation gets back to normal, he said.
There are a lot of the illegal diamond panners holed up in the mountains…playing a cat and mouse game with the police.
He said more police were to be deployed in the area.
Nearly 300 illegal panners and 100 vendor have been arrested; nine vehicles have been impounded, and eight diamond pieces have been recovered.
Meanwhile, the Reserve Bank of Zimbabwe chief, Gideon Gono, has admitted the country is losing more than US$8m worth of diamonds to smugglers each month.