(AFP) - Five African heads of state on Wednesday voiced "strong concern over acts of violence" during the presidential campaign of the Democratic Republic of Congo, where voting has been postponed in two restive regions.

Clashes in some locations are enough "to compromise voter's peace of mind," added a statement issued at the end of a one-day summit held in the neighbouring Republic of Congo.

A DRC representative was not present, but summit leaders decided that a delegation of foreign ministers would present "their conclusions" to DRC President Joseph Kabila on Thursday.

About a dozen people have died in DRC campaign violence according to various sources, which Kabila's government has denied.

Opposition candidate Martin Fayulu also claims that he was prevented from visiting three cities, Kindu, Kolwezi and Kinshasa, during the campaign.

On Wednesday, eight nations in southern and central Africa mulled the situation in DRC, a country that has been a regional battleground twice in the last quarter-century.

The mini-summit was held in Brazzaville, four days before problem-strewn elections across the border.

African leaders focused on "the electoral process in the DRC," said Cyprien Sylvestre Mamina, secretary general for foreign affairs in the Republic of Congo.

The meeting brought together many members of the the Southern African Development Community (SADC) and International Conference of the Great Lakes Region (ICGLR).

Those attending were Angola, Botswana, Congo, Namibia, Rwanda, South Africa, Uganda and Zambia.

Five countries were represented by their presidents, while the others sent foreign ministers or lower-level officials.

The DRC elections are to choose a successor to President Joseph Kabila, in charge of the volatile mineral-rich country for nearly 18 years.

Kabila was to step down at the end of 2016 after reaching his constitution-limited two terms in office.

But he stayed on, invoking a caretaker clause in the constitution.

The elections were postponed until the end of 2017 under a deal brokered by the powerful Catholic church -- and then again until 2018, when Kabila eventually confirmed he would not run again.

The country's election commission then moved the date from December 23 to December 30 after a fire destroyed voting equipment.

On Wednesday, the panel said that voting in two regions hit by violence, Beni-Butembo and Yumbi, would be postponed to March.

Despite this, the timetable for the presidential elections is not to be affected, with the next head of state still scheduled to be sworn in on January 18, the commission said.

© Agence France-Presse