Congolese security forces shot dead at least six people and wounded dozens more as they fired tear gas to disperse a rally against President Joseph Kabila organized by the Catholic Church on Sunday, a U.N. peacekeeping mission in the country said.

Kabila's refusal to step down at the end of his mandate in December 2016 has triggered a series of street protests in which scores have been killed in Kinshasa. It has also emboldened armed rebel groups in different parts of the country.

A Reuters witness saw police and paramilitary troops fire volleys of tear gas and shoot into the air on Sunday outside the Notre Dame cathedral in the capital Kinshasa.