Some 1,400 civilians have been killed in southern Sudan this year, many by ill-disciplined former rebels incorporated into the security forces before its secession, a senior U.N. official said on Wednesday.

Deputy High Commissioner for Human Rights Kyung-wha Kang told reporters that to halt such mayhem it was vital for the police and army of the new state to be trained and for their work to be observed by human rights monitors.

"Our information is that at least 1,400 civilians have been killed in south Sudan this year alone," said Kang, who has just returned from a visit there. South Sudan is due to become independent from the north on July 9.

"There is a lot of internal conflict over cattle and cattle-rustling, but there is also a great deal of violence by the SPLA," she said, referring to the Sudanese People's Liberation Army of the former rebels against Northern rule.

"Former combatants are being integrated into the army and police without discipline ... This is a very ill-disciplined military," Kang, a national of South Korea, told a news conference.

She said a major training effort was needed by the international community as well as by the new government.

"There is a tremendous need for the basic infrastructure for a functioning state which is just not there after many years of civil war," Kang added.

She said she hoped that a U.N. military peacekeeping force being put together for the disputed Abyei border region would have with it a strong contingent of human rights experts who would be able to monitor the situation anywhere in the country.

Clashes along the ill-defined border have raised fears of a return to the all-out north-south civil war that killed more than 2 million people over decades until 2005.