Sudanese President Omar al-Bashir is to make a rare long-distance visit to China, the foreign ministry said Sunday, despite an International Criminal Court indictment for alleged war crimes in Darfur.

Bashir is to attend September 3 celebrations marking Japan's defeat in World War II and meet his Chinese counterpart, a foreign ministry spokesman said.

South Sudan's army and rebels accused each other of responsibility for fresh fighting Saturday in the north-east in breach of a ceasefire to end a brutal 20-month civil war due to come into force later in the day.

"Riek Machar's rebels attacked Malakal yesterday," Friday, and the "assault on Malakal resumed this (Saturday) morning," army spokesman Colonel Philip Aguer said at a press conference. "That's untrue, their forces attacked us near Malakal," rebel spokesman James Gatdet Dak told Agence France Presse.

A deal signed by South Sudan's president aimed at ending 20 months of civil war was given a cautious welcome Thursday, with both sides in the conflict urged to show good faith.

At least seven ceasefires have already been agreed and then shattered within days or even hours in South Sudan, which broke away from Sudan in 2011.

Sudan has failed to investigate serious human rights violations, including rape and murder, in the Darfur region, a fresh report said Friday, as the U.N. rights chief decried "endemic impunity" in the region.

The report by the United Nations rights agency documents more than 400 serious rights abuse cases in Darfur last year, affecting nearly 1,000 people, including cases where Sudanese police and security forces allegedly attacked and killed civilians.

Sudanese President Omar al-Bashir said Thursday he was ready for a two-month ceasefire with rebels to allow national dialogue talks to take place to address the country's myriad problems, offering insurgents an amnesty.

Bashir, who is wanted for alleged war crimes in Darfur, announced the talks in January 2014 to resolve conflicts in Sudan's border regions and has been trying to persuade rebels to attend the talks in Khartoum.

At least eight people were seriously injured Sunday when a helicopter from the U.N.-AN peacekeeping mission in Darfur made an emergency landing in the western Sudanese region, the mission said.

"A UNAMID helicopter, an Mi-8, carrying 18 passengers and three crew on board made an emergency landing approximately 100 meters" (yards) from the helipad at a base belonging to the mission at Saraf Omra in North Darfur, spokesman Ashraf Eissa told AFP.

South Sudan's government said Saturday it would continue with peace talks to end a 20-month civil war, but without  President Salva Kiir attending, his spokesman said.

"We are still engaging in the peace efforts, that has not stopped," presidential spokesman Ateny Wek Ateny told Agence France Presse, a day after government officials had said talks in Ethiopia would be suspended.

Amnesty International said on Tuesday that the Sudanese army had committed war crimes in the conflict-hit South Kordofan region, including bombing and shelling civilian areas and infrastructure.

Government forces have been facing a rebellion in the South Kordofan and Blue Nile states by the Sudan People's Liberation Army-North since 2011.

Sudan's government said Monday it is ready to offer rebels battling its forces legal guarantees to allow them to attend talks in Khartoum aimed at addressing the country's multiple crises.

President Omar al-Bashir has called for a national dialogue to try to end conflicts in border regions and to right its ailing economy.

African leaders issued a joint statement from a conference in Mauritania on Monday calling for the lifting of sanctions against Sudan, whose president is wanted for a string of atrocities.

Omar al-Bashir -- indicted for genocide in Sudan's western region of Darfur -- was among 11 leaders or government representatives at the meeting in Nouakchott of countries grouped by the "Great Green Wall" ecological initiative.