UN concerned over attack by South Sudan opposition

UN Secretary-General Ban Ki-moon Sunday expressed his deep concern over a major attack by South Sudan opposition forces, which further threatened a shaky peace agreement.

"It undermines ongoing intense regional and international political engagement toward a resumption of political negotiations and a peaceful resolution of the South Sudan conflict," Xinhua quoted a statement issued by Ban's spokesperson as saying.

Under the command of former South Sudan vice president Riek Machar, the opposition forces attacked Nassir in the Upper Nile State earlier in the day. It was the first major attack since the South Sudanese government and opposition recommitted to a ceasefire agreement signed in May.

Ban called on Machar to cease all offensive operations on Nassir and other points, and on the government to "desist from launching a counter-offensive", it said, adding that the UN chief urged both parties to stop the violence immediately, reconvene political negotiations.

Last year, political infighting between President Salva Kiir and Vice- President Machar, who is accused of leading a military rebellion against the government, turned into a full-fledged conflict.

Kiir and Machar signed an agreement in Addis Ababa, Ethiopia, May 9, which stipulates comprehensive ceasefire and formation of a transitional government to arrange for general elections within a year from the signing of the deal.

But clashes between the two sides were reported despite the agreement.