At least 10 subsistence miners have been killed after a mine dump collapsed in Kitwe, Zambia's second-biggest city and copperbelt mining hub, police have said.

"So far we have retrieved 10 dead bodies and seven bodies of those injured," Copperbelt province police commissioner Charity Katanga was quoted by AFP news agency as saying.

More than 20 young miners are feared dead, the Zambian Watchdog news site reports.

Others miners have assaulted people taking photos of the scene, it adds.