The UN has confirmed Southern Sudanese claims that its territory has been bombed ahead of January's independence referendum.
Southern Sudanese leaders have accused the north of trying to jeopardise the vote.
The northern military - which has the area's only air force - denies it carried out the bombing.
Military leaders from the two sides are to meet, along with UN officials to try to defuse tension ahead of the poll.
The 9 January vote on whether the south should secede from Africa's largest country is part of a 2005 deal to end two decades of war between the mainly Muslim, Arabic-speaking north and the south, where most are Christian or follow traditional local religions.
Although no-one was killed in the bombing in Timsaha in Western Bahr al-Ghazal province last Wednesday, the SPLM which already governs Southern Sudan, has called for a UN commission of inquiry.
It has said its territory has been bombed on several occasions in recent weeks.
The north has always denied all the accusations it faces.
The BBC's Peter Martell in the southern capital, Juba, does note that the north has accused the SPLM of sheltering rebels from the Darfur province which borders Western Bahr al-Ghazal.
The UN sent a team to investigate the reports.
"After verification it was established by the [joint ceasefire commission] members that air attacks took place," said UN spokesman Kouider Zerrouk.