At least two people were killed and hundreds of ruling party supporters stormed Kinshasa cathedral in the capital of the Democratic Republic of Congo this weekend after the authorities there banned a planned church-backed rally against the country's president, Joseph Kabila.

The ban on Sunday's anti-Kabila march came after a total of 15 people were killed by security forces in previous protests on New Year's Eve and January 21, according to organisers and the UN. The government claims that only two people died at those protests, and denied that any had died this weekend.

'We have come to take possession of Our Lady of the Congo Cathedral to take part in Sunday mass... and defend the homeland,' Papy Pungu, the youth wing leader of the People's Party for Reconstruction and Democracy (PPRD), told AFP, vowing to 'spend the night here'.

Catholic and evangelical churchgoers across Congo had meant to take to the streets following Sunday services, but they were met with police and soldiers deployed to stop them.

In addition to the dead, who were killed in the capital Kinshasa and the western city of Mbandaka, the head of Congo's UN mission, Leila Zerrougui, said 47 people were injured and more than 100 were arrested across the country. She called on the Congolese authorities to carry out credible investigations into the incidents and impose appropriate sanctions.

National police spokesman Colonel Pierrot Mwanamputu told state broadcaster RTNC that there had been no deaths and only three people were wounded in Sunday's violence.

In power since 2001, Kabila struck a deal with the main opposition bloc to stay on after his elected mandate expired in December 2016, but authorities missed a deadline to hold elections last year as required under the agreement.

Officials have hinted that a new December poll date may not even be possible due to financial and logistical constraints.

Church groups have emerged as the main force opposing Kabila as political opposition parties have been hobbled by infighting or seen their leaders forced into exile.

'Our people no longer believe in the political will of our current leaders to ensure a peaceful transition of power,' one of the main organising groups, the Lay Coordination Committee (CLC), said in a statement before the march.

The organisers are demanding the prompt organisation of elections and a pledge from Kabila not to stand for re-election.

However, armed security forces surrounded Kinshasa's main churches and blocked roads, preventing most demonstrations from starting and in some cases using teargas and gunfire to disperse them.

The march organisers, the CLC, said it had confirmed three deaths on Sunday, one more than the UN – two in Kinshasa and one in Mbandaka. The figures could not be independently verified. Witnesses and rights groups also reported violence in the northern city of Kisangani.

Witnesses told AFP that the arrival at the cathedral of the PPRD supporters, many wearing red berets, resulted in panic at the capital's northern Lingwala municipality.

'They arrived aboard several Transco (public transport) buses and stormed the shrine of the Virgin. It's a provocation,' a local parishioner, Felicite Mbula, told AFP.

'The church is closed, we couldn't hold mass this evening,' she added.

Antoine Bokoka, a parish official, told AFP that the PPRD were 'pretending to come to pray Sunday. But you don't stay overnight in our parishes'.

Additional reporting by Reuters.