A committee with representatives from the UN mission in Sudan and the northern and southern Sudanese militaries found that the bombings violated the agreement that ended more than 20 years of civil war, said UN spokesman Kouider Zerrouk.

The bombings in western Bahr El Ghazal state happened Dec. 6, Dec. 8 and Dec. 9. No casualties were reported, but they follow multiple bombing runs by the north in November in a disputed region on the border between neighboring northern Bahr El Ghazal state and southern Darfur state.

Zerrouk said it wasn’t clear if the November bombings were a violation of the peace agreement, but he said the northern and southern militaries agreed that those incidents were “unfortunate and should not be repeated.” The bombings come less than a month before Southern Sudan is scheduled to hold a Jan. 9 independence referendum that is likely to see Africa’s largest country split in two. The 2005 peace accord gives the south the right to the vote.

Diplomats, the UN and the African Union are working behind the scenes to ensure a peaceful vote. An Associated Press reporter last week visited the sites of the November bombings and saw multiple bomb craters and evidence that straw huts burned to the ground after the explosions. Southern military officials said they believed the bombings were provocations intended to ignite conflict and disrupt the referendum.

Thousands of civilians fled the site of the November bombings, and the southern military brought in three anti-aircraft guns as a defensive measure.

The total wounded in the attacks is believed to range from 16 to 22, with 10 to 11 of those being soldiers. No deaths were reported.

The joint UN-Sudanese committee — known as the Cease-fire Joint Military Committee — recorded the December bombings as a violation of the 2005 agreement despite an objection from the senior member from north Sudan, the UN said.

Meanwhile, the Carter Center — the largest international mission observing the referendum — said late Wednesday that the three-week registration process of southern voters was “generally credible.” The final voter list is not scheduled to be published until Jan. 8, one day before voting begins.

A group of lawyers from Khartoum has said they will file a lawsuit to challenge the registration process, and a group claiming to represent Southern Sudanese groups filed a similar suit.

The head of the referendum commission’s bureau in the south has dismissed the complaints as “baseless, frivolous, and politically motivated.” “If the referendum is delayed, I think the repercussions could be great in terms of violence and in terms of confidence and the trust between north and south,” said Chan Reec Madut, the head of the Southern Sudan Referendum Bureau.

The Southern Sudan Referendum Commission says more than 3.2 million people registered to vote in the south — 96 percent of the eligible population.

Northern and southern officials continue to negotiate over key issues such as citizenship, wealth-sharing, demarcation of the border and the status of the region of Abyei. That region had also been scheduled to decide on Jan. 9 whether to join the north or south, but the US said last week that Abyei’s vote won’t happen and that the region’s status is likely to be decided through talks.