Sudanese warplanes hit Southern border regions, Southern army officials said Thursday, the latest violence in weeks of clashes that have sparked international condemnation and calls for restraint.

Antonov bombers and MiG fighter jets attacked the village of Chotchare in the South's Unity state late Wednesday, but there were no immediate reports of casualties, said Southern army spokesman Philip Aguer.

Khartoum's Sudan Armed Forces (SAF) "has not stopped its aggression," said Aguer, adding that Wednesday's bombing mainly targeted the temporary settlements of cattle-herding pastoralists.

The reported attacks could not be verified independently, and Sudan has repeatedly dismissed Southern reports of attacks.

US Secretary of State Hillary Clinton on Tuesday denounced air strikes on South Sudan as "provocative and unacceptable" and called on the two sides to resume talks as soon as possible.

Heavy fighting broke out earlier this month between the rival armies, as Southern troops seized the contested Heglig oilfield from Khartoum's army, pulling out 10 days later after international pressure.

However, Sudanese warplanes bombed their forces as they moved southwards as well as hitting Unity state capital Bentiu, attacks which South Sudan President Salva Kiir said Tuesday was a declaration of war by Khartoum.

Last week, Sudan's President Omar al-Bashir threatened to crush the "insect" government of the South, and said the time for talks was over.