Long-delayed peace talks between Sudan's government and two rebel groups from the country's western Darfur region resumed Friday in Nigeria's Abuja, with both sides expressing cautious optimism for the talk's outcome.

Sudanese officials and top rebel leaders, including Mohammed Al-Nour of the Sudan Liberation Movement (SLM) and Ibrahim Khalil of the Justice and Equality Movement (JEM), attended the talks held in Abuja, Nigeria's capital, the fourth round since August last year.

Alpha Oumar Konare, chairman of the African Union Commission, opened the talks and said he hoped this round could be the last one.

"No efforts should be spared by the parties in reaching agreement on the cessation of attacks, intimidation and other forms of violence against civilians," said Obasanjo, also president of Nigeria, who is now out of the country, in a speech read on his behalf.

Obasanjo condemned recent fighting for territory between the two rebel groups themselves, which killed 11 people and injured 17 others.

"It is unfortunate that there remains continued violence and instability in the region caused by continued violation of ceasefire and signed agreements," Obasanjo said.

He challenged all parties involved in the crisis to "refrain from violence" and "abide by the agreements already entered into" as Sudan needed stability to prosper.

Obasanjo's spokeswoman Remi Oyo told Xinhua early this week that the president is also hoping the talks could make a final resolution to the Darfur crisis that flared up in February 2003.

Thousands of people have been killed and over a million driven from their homes during the two-year fighting in Sudan between the rebels and government troops.

The African Union has brokered a shaky ceasefire and struggled to find a political solution through three previous rounds of Abuja talks which ended in December last year.

And this time, after a six-month gap, both the government and the rebel groups said they are optimistic that the talks could make some agreement for peace in Darfur.

"We are optimistic that at the end of ... talks, we shall reach a resolution of the crisis to the satisfaction of the peoples of Sudan, the African Union and the rest of the international community," said Sudanese Agriculture Minister Maghzoub El-Khalifa, who heads the government delegation.

Al-Nour, lead of the SLM also said: "We are here to reach a comprehensive peace... if Khartoum is as ready as we are."

According to the AU, the Sudanese government has stopped bombing operations in Darfur, and has made significant progress in meeting the rebel's demand, which has stalled earlier talks.

(Xinhua News Agency June 11, 2005)