Harare - Hundreds of companies have applied to mine in Zimbabwe's Chiadzwa diamond fields, which were marred in recent years by human rights abuses, media reported Thursday.

'We have received 400 diamond mining applications and we are processing them,' said Mines Minister Obert Mpofu. Only five companies reportedly have licences at present.

Mpofu, a close ally of President Robert Mugabe who has so far handpicked the companies allowed to mine the Chiadzwa diamond fields in Marange district, defended gems mined in the area, in comments quoted by the private Newsday newspaper.

Zimbabwe's diamond industry was badly tainted by allegations of rights abuses in 2008, when up to 200 miners were reported killed by Mugabe's military in Chiadzwa.

The globally respected diamond watchdog, the Kimberley Process Certification (KPC) Scheme, has been racked by squabbles over whether Zimbabwe should be legally allowed to export its gems.

'We will not pull out of the KPC,' said Mpofu, adding, 'There is nowhere in the world where systems are as impeccable as Marange.'

However, human rights groups say that Zimbabwe has failed to put an end to malpractice which allegedly includes police and military abuses in the fields, involving killings, beatings, forced labour and smuggling.

According to official figures, Zimbabwe exported 716,958 carats of raw diamonds from January to June 2011, raising 103.9 million dollars. Critics say many more gems are being smuggled out of the country.

In separate comments, Mpofu said the authorities did not intend to cancel any mining licences for foreign companies engaged in extracting other minerals in Zimbabwe.

His comments contradicted earlier threats from Indigenisation Minister Saviour Kasukuwere, who last week announced that he wanted to cancel operating certificates for more than 50 firms that had allegedly not complied with new black empowerment regulations.

'We have no intention of cancelling any licences,' Mpofu told delegates at a conference in Harare. 'There are some negotiations taking place with some parties.'