Sudan Abyei shooting a 'pretext for war'
Shooting on Monday night by northern Sudan soldiers was an attempt to start clashes in the oil-rich region of Abyei, southern former rebels say.
SPLM spokesman Kuol Deim Kuol said four soldiers went into Abyei town's market and fired at random, wounding a trader.
He told the BBC it was a pretext to start trouble, as UN-mediated talks on Abyei's referendum ended in failure.
The people of Abyei are due to vote in January on whether the region should belong to north or south Sudan.
It is scheduled to take place on the same day as the south holds a referendum on whether to secede from north Sudan.
Both referendums were part of a 2005 peace deal to end two decades of conflict between the north and south, in which some 1.5 million people died.
Units of northern soldiers and southern SPLA soldiers are stationed in Abyei, where there are still disputes over voter eligibility and the physical demarcation of the state's border.
Lt-Gen Kuol said northern soldiers in barracks in Abyei town responded to the market gunfire by firing in the air from about 2100 until 0200 on Tuesday morning.
The SPLM spokesman said the shooting only stopped after the intervention of UN peacekeepers.
"They want to provoke a fight - and there was no fight simply because the SPLA officers who are part of the joint integrated unit managed to control the SPLA soldiers and they did not fire," he told the BBC's Focus on Africa programme.
"They want to dishonour the peace agreement and they're looking for a scapegoat. It's just a pretext to start a war," he said.
Correspondents say there is much suspicion in the south that President Omar al-Bashir and his colleagues in the north are doing all they can to stop the referendum because they stand to lose out on vast amounts of oil in Southern Sudan.
BBC East Africa correspondent Will Ross says the week-long talks in the Ethiopian capital, Addis Ababa, on organising Abyei's referendum ended without agreement as northern politicians refused to recognise last year's international court ruling in The Hague fixing the region's borders.
But President Bashir's security advisor Salah Gosh blamed the breakdown in the talks on the SPLA.
He also denied suggestions the north was trying to delay or block the vote.
"We are working hard to run the south-north referendum," he told Focus on Africa.
The other more serious point of disagreement has been about who should be able to vote on 9 January.
Abyei is home to both the Dinka ethnic group, seen as supporters of the south, and the nomadic Arabic-speaking Misseriya people, seen as northerners.
The SPLM do not think the Misseriya, who spend several months of the year in Abyei and have grazing rights in the region, should have the right to vote.
The negotiators have agreed to reconvene at the end of October.
At least 100 people died and 50,000 people fled their homes in heaving fighting in Abyei two years ago.