Human rights groups want some major banks to reevaluate their ties to banks in Zimbabwe, saying the relationships indirectly support the trade in so-called “blood diamonds.”

Partnership Africa Canada says the banks, including Britain's Barclays and South Africa's Standard Bank, are not involved in the Zimbabwe diamond trade. But the group's research director says they partner with Zimbabwean banks that have ties to the disputed Marange diamond fields.

Barclays Bank and Standard Bank have not yet responded.

Rights groups have accused Zimbabwe's military of killing local miners and running a forced labor operation in the fields.

As a result, sales of diamonds from Marange have been restricted by the Kimberly Process, the consortium set up to stop the export of blood diamonds.

Blood diamonds are gems mined and sold to finance war or violence, usually in Africa.

Partnership Africa Canada said Tuesday it has linked three Zimbabwean banks to the Marange diamond trade, including BancABC and Commercial Bank of Zimbabwe.

Meanwhile, a report released Tuesday by the human rights group Human Rights Watch says Zimbabwean police, along with guards employed by private mining companies, have been attacking miners suspected of illegally digging in Marange.

The report says the police and guards shoot, beat and use dogs to attack the miners, calling the actions “inhuman, degrading and barbaric.”