An emergency regional summit planned for Thursday in the capital of war-torn South Sudan has been cancelled, official media in Khartoum said.

The East African regional bloc IGAD has been mediating in talks in Ethiopia between troops loyal to President Salva Kiir and rebels allied to his sacked deputy, Riek Machar.

Sudan's President Omar al-Bashir will travel Thursday to the capital of war-torn South Sudan to push peace efforts in a regional summit, the official SUNA news agency said on Monday.

The invitation came from Ethiopian Prime Minister Hailemariam Desalegn, chairman of the seven-member Intergovernmental Authority on Development (IGAD), an East African bloc mediating the South Sudanese conflict.

Rebels in Sudan's Blue Nile state on Sunday claimed to have killed dozens of soldiers and disabled a tank during battle, but the military said it was the victor.

The Sudan People's Liberation Army-North said it "managed to destroy" a government convoy at Malkan on Friday.

South Sudan's government said Saturday it was optimistic it may soon sign a ceasefire agreement with rebels, amid the first signs that peace talks underway in neighboring Ethiopia could be making progress.

A spokesman for President Salva Kiir said the government's chief negotiator, who had been back in Juba for consultations, was preparing to return to Addis Ababa intent on signing a truce.

Some walked, others were luckier and hitched a ride, but all ended up under the sun at a Sudanese border checkpoint, waiting to cross and leave South Sudan's war behind.

Hundreds of crying children and exhausted adults have converged on the border post at Joda, where Sudan's White Nile state meets the South's Upper Nile, which saw heavy fighting this week.

South Sudan's army said Friday it has been unable to contact its forces fighting in the key oil-town of Malakal as rebels claimed to control it.

Malakal, the main town in northern Upper Nile state, has become one of the most bitter battlegrounds in the conflict now raging for over a month in the world's youngest nation.

A Sudanese migrant froze to death in Estonia in an ill-fated illegal crossing of the EU-Russia border, police said Thursday.

The 54-year-old man and two other surviving Sudanese men crossed a river from Russia to reach Estonia, a member of the European Union since 2004, police spokesman Kerly Peitel told Agence France Presse, noting temperatures had plunged below minus 10 degrees Celsius (14 Fahrenheit).

Britain Thursday praised Sudan's role in supporting efforts to bring peace to its former foe South Sudan, where thousands have been killed over the past month.

"I very much commend Sudan for the balanced role it has played so far in support for the IGAD-led negotiations," Mark Simmonds, the British minister for Africa, told reporters after a two-day visit to Khartoum.

Around 10,000 people have fled north to Sudan from South Sudan where government troops and rebels have battled for the past month, the U.N.'s refugee agency said on Sunday.

"10,000, this is something we are confident with, that these are confirmed people who have crossed the border, who have been fleeing the conflict," Nicolas Brass, external relations officer with the United Nations High Commissioner for Refugees (UNHCR), told Agence France Presse.

Sudan said on Saturday it disarmed more than 50 fighters from the southern Nuer tribe who crossed the border, in the first such incident since fighting began between the South Sudan army and rebel troops.

South Sudan rebel leader Riek Machar is from the Nuer tribe while President Salva Kiir belongs to the majority Dinka.