Dozens reported dead in South Sudan attack

Attacks in South Sudan has left 50 villagers dead, a military spokesman says, while a local official in Jonglei state puts the number at more than 70.

South Sudan raised the flag of its new nation for the first time on July 10, 2011, as thousands of South Sudanese citizens swarmed the capital of Juba to celebrate the country's birth. (AP)

Dozens of people have been killed in an attack on South Sudanese villages by a rebel group and local tribesmen, officials say.

The attacks on Sunday left at least 50 people dead, said military spokesman Philip Aguer, while a local official in Jonglei state said the number was more than 70.

Rebel fighters from David Yau Yau's anti-government militia appear to have teamed up with ethnic Murle fighters who have been locked for years in running battles with the rival Dinka people, often launching attacks over cattle.

Aguer said the attackers were armed with automatic rifles and rocket propelled grenades.

Women and children were among the dead and injured and up to 20 children may have been kidnapped during the attacks, which saw two villages largely razed to the ground.

Thousands of cattle were taken in the raids, the latest in a long string of tit-for-tat attacks in Jonglei, an area prone to ethnic rivalries and where there is a widespread proliferation of weapons.

"The people are living in fear. They need protection," said local official Dau Akoi Jurkuch.

The UN helped to ferry the wounded to clinics, and local police units were sent to the area, in the east of South Sudan.

The government in Juba has been accused by the Murle of siding with the Dinka in Jonglei.

Yau Yau, a rebel who integrated into the army when South Sudan was becoming independent in 2011, but defected again a year later, is Murle, as are many of his fighters.