EU lawmakers have backed tougher rules to limit the import of conflict minerals.

A European Parliament committee said it should be more difficult for military groups to finance their activities by selling precious minerals.

MEPs want a system of self-certification to be mandatory, rather than voluntary as the European Commission had proposed.

That would mean companies would have to prove that all resources throughout their supply chain were ‘conflict-free’.

The US already has legally binding requirements, which focus on the Great Lakes region in Africa.

The EU’s draft law may not just apply to sub-Saharan Africa.

For example it could apply in Colombia, where militias control some gold mining regions.