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British Foreign Secretary Jack Straw (search), touring a sprawling desert camp housing 40,000 displaced people from the troubled western Darfur region, urged the Sudanese government to do more to make it safe for the frightened refugees to return home.

Welcomed by women in brightly colored robes and high-pitched trills of greeting, Straw visited the conflict-ravaged region as a U.N. deadline neared for Khartoum (search) to disarm Arab militiamen, accused of terrorizing African farmers, or face economic and diplomatic sanctions.

More than 30,000 people have been killed and 1.4 million forced to flee their homes in what the United Nations has described as the world's worst humanitarian crisis. Some have gone further, calling it genocide, a designation many believe would force the international community to take strong action.

In Nigeria, Sudanese officials and rebels gathered for a second day of talks, struggling with mediators to reach an agreement toward easing the crisis.

On Monday, Khartoum defied international pressure and rejected a wider role for African peacekeepers in monitoring Darfur. Straw had said earlier that Britain would have provided increased funding for an expanded African Union (search) force.

The Nigeria talks are a last-minute attempt for progress before the U.N. Security Council's Aug. 30 deadline for Khartoum to disarm the Arab militia known as the Janjaweed (search) or face economic and diplomatic sanctions.

Straw, whose country has veto power on the Security Council, said officials should be in a position by the end of the week to decide whether Khartoum had made sufficient progress toward stemming the violence and allowing humanitarian aid to avoid sanctions.

"It is for [U.N. Secretary Genera] Kofi Annan to judge the extent to which they have complied," Straw said, sweating in the searing desert heat, before leaving Darfur for talks in the capital with Sudanese President Omar el-Bashir (search).

Aid agency representatives said the security presence at the camp was significant Tuesday, unlike typical days without visiting dignitaries. Blue-uniformed police clutching rifles were visible at regular intervals in the camp, one of 147 in Darfur, a western region the size of France.

Although well organized with water points, latrines and some medical facilities, aid workers say the camp has one of the highest malnutrition rates in the Darfur region. They also report that some Sudanese police responsible for protecting the refugees are sexually exploiting women in the camps.

Brightly dressed women clamored around Straw at a watering point in the Abu Shouk camp near Al-Fasher, the provincial capital of northern Darfur. Some carried babies in slings on their backs, others let out high pitched trills in a traditional welcoming cry to the British delegation.

Straw said it was clear from their stories that many would not return to their villages because of fears of attacks by the Janjaweed.

He said there had been progress since the Security Council set the deadline, noting that humanitarian aid groups had been granted access to the western region and that security in the camps had improved.

But "people are still very anxious, apprehensive and nervous about whether they will be safe to go back to the villages from which they have come," Straw said. "There is still a lack of confidence that it is safe for them to return home, and that has got to be pinned down."

In the Nigeria talks Tuesday, Sudanese insurgents said they won't lay down their weapons until Arab militiamen stop terrorizing black Africans.

"The Janjaweed are carrying out ethnic cleansing and genocide. If there is a security arrangement, disarmament will come gradually. But now we are not ready to speak about disarmament," said Abdelwahid Muhamed El Nur, chairman of the Sudan Liberation Army (search).

Straw did not respond directly when asked whether he saw evidence of ethnic cleansing and genocide.

"People here have suffered grievously," he said. "People have lost their lives and they have lost their loved ones. People have been injured and because children have been uprooted, many are suffering from malnutrition. The crucial challenge now is not the description, but what we do about the problem and how we try to turn it around."

Straw spent some 90 minutes touring the camp dotted with makeshift straw and tarpaulin shelters. Children ran excitedly around him as he spoke with aid agency officials. In a medical tent, Straw saw babies with tubes inserted into their noses, crying in their mother's arms.