Congolese security forces shot dead a man and injured several others on Sunday in a bloody crackdown on Catholic worshippers who gathered at churches across the country to demand President Joseph Kabila leave power.

AFP reporters witnessed the latest of several recent outbreaks of bloodshed in the vast, mineral-rich central African country, wracked by tension over delayed elections.

An AFP reporter at a demonstration in the central city of Kananga saw a man shot in the chest by soldiers who opened fire on worshippers gathered for what church leaders said would be a peaceful protest.

Elsewhere, troops fired tear gas and bullets in the air to break up gatherings at Catholic masses across the capital Kinshasa, in one case arresting 12 altar boys who were leading a protest.

Protest banned

Church and opposition groups defied a ban by authorities to push ahead with the demonstrations.

The protesters were demanding that Kabila promise he will not seek to further extend his time in power in DR Congo, a mostly Catholic former Belgian colony.

Kabila has been in power since 2001. Elections to replace him have been delayed and are currently set for December 2018.

The United Nations says dozens of people have been killed during anti-government protests this year.

Impatience boiled over on Sunday, with all the vast central African country's main opposition and civil society groups joining in the call for peaceful protests.

Priest, woman hurt

In Kinshasa, AFP counted about 10 people hurt, including a priest with an injury to the face and a woman in her sixties with a gash on her forehead, after police broke up church gatherings.

One army officer threatened a team of AFP reporters covering the crackdown at St. Michael's church in Kinshasa.

"If you don't clear out of here, I'll order that you be shot at," he said.

"Press, or not, no one is allowed inside. What's more, you have a white man with you — that's a race that causes us problems."

A journalist for French radio station RFI was briefly detained, AFP reporters saw.

Soldiers storm church

A churchgoer who asked not to be named described to AFP how officers dispersed worshippers from one mass.

"While we were praying, the soldiers and the police entered the church compound and fired tear gas at the church," he said.

Another parishioner who identified herself as Chantal said: "People fell, first-aiders are resuscitating old ladies who have fallen" — but added that the priest carried on saying mass.

Officers later detained 12 altar boys dressed in their liturgical robes outside one church as they led a protest march.

Other protesters went back inside the church grounds and started singing for the Virgin Mary to "make Kabila go".

Elections delayed

In Kinshasa, Catholics of the "Lay Coordinating Committee" had invited worshippers to walk, holding bibles, rosaries and crucifixes, after mass on Sunday.

They want Kabila, 46, to declare publicly that he will not run for another term as president.

The country has not had a peaceful transition of power since independence from Belgium in 1960.

Kabila succeeded his assassinated father Laurent Kabila in 2001 and refused to step down at the end of his second and final term in December 2016.

That refusal led to protests and a bloody crackdown.

Elections had been due to take place by the end of this year under a church-mediated deal.

The delayed poll is now scheduled for December 23 next year, further angering Kabila's opponents.

'Insurrection' plan alleged

Government spokesman Lambert Mende alleged in televised comments that "weapons of war have been distributed" by opponents of the government.

"These destabilising acts of agitation aim to create an atmosphere of insurrection which would enable them to seize power in our country by undemocratic means," he said, citing a government report.

International powers such as the United Nations have called on the Congolese authorities to allow peaceful protests.