Tensions are running high in Darfur, one day before a deadline expires for two holdout rebel groups to sign a peace agreement. The African Union says it has witnessed increased violence against its troops in the region since May 5, when the Darfur Peace Agreement was completed.

An A.U. spokesman says peacekeepers have been targeted by groups who seek to undermine the Darfur Peace Agreement, citing increased attacks in recent days.

A Nigerian peacekeeper was killed in an ambush on Friday, and six others wounded. The same patrol was attacked again a day later.

A.U. spokesman Nourredine Mezni told VOA from Khartoum that misinformation about the peace agreement has led to violent reprisals against A.U. troops, although the African Union is uncertain who the attackers are.

"There are some inciters from outside, from some parties, who are opposed to this peace agreement," said Mezni. "That is why we have these attacks against our troops in Darfur, because the population look at the troops as a symbol of the Darfur Peace Agreement. The attacks against humanitarian workers, attacks against AMIS [African Mission in Sudan] troops, demonstrations, because there is misinformation on this agreement."

Mezni says the African Union is launching a media campaign to urge Darfuris to support the peace deal.

The underfunded African Union force has only about seven-thousand troops patrolling a remote area the size of France.

The international community has called for A.U. troops to be replaced by U.N. peacekeepers with increased numbers, a larger budget, and a stronger mandate.

Meanwhile, a deadline for two holdout rebel groups to sign on to the agreement expires May 31.

One faction of the Sudan Liberation Army led by Abdel Wahid Mohamed Nur and the politically savvy Justice and Equality Movement, have been threatened with sanctions if they refuse to sign on.

Menzi said the A.U. Peace and Security Council is considering what actions to take if the two groups do not sign the agreement.

Ambassdors from the U.N. Security Council, which put heavy pressure on Khartoum to allow a U.N. force into the region, are to arrive next week in Sudan to assess the situation.

The three-year Darfur conflict began when rebels attacked government positions complaining that the remote region remained undeveloped due to neglect. The Sudan government is charged with arming local Arab militias to conduct a campaign of rape and murder, a charge it denies.

Tens of thousands have died and about two million people have been displaced in what the United States calls genocide.