The presidents of Chad and Sudan have signed an agreement to stop destabilizing each other's country after several hours of meetings in the Senegalese capital, Dakar. But analysts and officials agree there are remaining challenges to end the violence in a region with many rebel and militia groups. Nancy Palus in Dakar has this report for VOA.

Sudanese President Omar al-Bashir and Chad President Idriss Deby shook hands on the red-carpeted steps of the Senegalese presidential palace at around 11:00 p.m. Thursday, after hours of wrangling over the text of the agreement.

The single page of text, read by Senegalese Foreign Minister Cheikh Tidiane Gadio, reiterates the two sides' commitment to past agreements, signed in 2006 and 2007.

In the newest element of the accord, Chad and Sudan agree to the formation of an observer group - jointly led by Libya and the Republic of Congo - which will meet once a month and monitor compliance.

Chad and Sudan have long accused one another of trying to destabilize their respective countries by giving rebel groups safe haven and resources. Past agreements - which called on both sides to stop rebels from using their territory - have failed.

Samani al-Wasila is state minister for the Sudanese Ministry of Foreign Affairs. He says what is needed is the will to follow past accords, notably one signed in Tripoli in 2006.

"We do not need anymore agreements," he said. "What we need is a good will to implement what we had before. We had the Tripoli agreement, which is a wonderful agreement with all the mechanisms, all it needs is a will to implement it."

The Sudanese official says both Chad and Sudan must resolve rebellions within their own countries.

Talks are ongoing between Darfurian rebels, who have their political headquarters in Chad, and Sudan's government, for a new peace deal to end that conflict, but progress has been slow.

Meanwhile, Chad signed an agreement with its rebels last October, but earlier this year Chadian rebels nearly toppled Mr. Deby.

"Why it is not implemented it is not our concern. It is not that we could do it - we could not force them,Samani al-Wasila said. But, unless the Chadian government and the opposition reach an agreement there is no security in Chad or stability in Chad going to happen. Same thing in Darfur."

Kissy Agyeman is a sub-Saharan Africa analyst in London. She says Chadian rebels think they are fighting for a just cause.

"The niggling problem that the rebels have is the fact that Mr. Deby is in power and they consider him to be a tyrant who is exploiting oil wealth and so forth, she said. So arguably they will not rest until he goes or at least until some sort of agreement is reached."

The Chad-Sudan talks, mediated by Senegalese President Abdoulaye Wade, took place during a summit of the Organization of the Islamic Conference, or OIC, in Dakar.

U.N. Secretary-General Ban Ki-moon and other officials say the OIC has an important role to play in tackling conflicts around the world.

Ban Ki-moon spoke at the opening of the summit Thursday. He said a political solution is essential to resolving the region's conflicts.

"The OIC is well-placed to support this process," he said. "You can utilize your considerable influence on behalf of a lasting peace within and between Chad and Sudan and as you do so the UN will continue to do everything it can to help end the suffering in the region."

Just after the signing ceremony at the presidential palace, Senegalese artist Ismael Lo, seated in the candle-lit courtyard with his guitar, broke into one of his best-known songs, Jammu Africa, which in the local Wolof language means Peace in Africa.