The Sudanese Armed Forces on Saturday killed two people when they bombed a South Sudanese army position close to the town of Jau, which lies in a buffer zone along the common border, South Sudan's army said.

"The SAF carried out the bombing with MiG-29 fighter jets. They dropped two bombs on our defensive position in Jau yesterday," said James Kong Chuol, a major general commanding a division of the Sudan People's Liberation Army close to the border.

"An SPLA soldier and his wife lost their lives. Six other people including a four-year-old girl were injured," Chuol told AFP on Sunday.

Chuol said SPLA's foremost positions are now in South Jau. They pulled back 10 kilometres (6 miles) from earlier positions in North Jau to comply with a border security mechanism agreed on at peace talks in September 2012.

The mechanism provides for a distance of 20 kilometres (12 miles) maintained between Sudanese and South Sudanese forces along the border.

Chuol said the attack was a "provocation".

"If they continue it is up to us to decide" whether to retaliate," he said, adding he had instructed his men to be on high alert.

Jau, in Unity state's Pariang County, has been bombed by the SAF before, notably in February and July of this year.

The latest incident comes just days after an apparently harmonious conclusion to a one-day summit between the two former civil war foes.

Sudanese President Omar al-Bashir met his South Sudanese counterpart Salva Kiir in Khartoum on Tuesday.

The two leaders averted a shutdown of economically vital oil flows. They also pledged to implement a raft of measures they agreed to in September of last year Implementation was derailed by a series of disputes between Sudan and South Sudan, which claimed independence and broke away in July 2011.