Fighting is continuing in Sudan's war-torn Darfur province, where rebels are trying to take a government-held town, the UN says.
Even in camps, many refugees do not feel safe
The clashes have prompted aid agencies to pull out of the area around Golo. The US has condemned the rebel attacks.
One of the Sudanese aid workers being evacuated was killed on Wednesday when a UN helicopter crashed.
More than two million people have been forced from their homes and at least 180,000 have died in the conflict.
"Fighting is still continuing with heavy weapons" in the West Darfur town of Golo, said UN spokeswoman Radhia Achouri.
She urged all sides to cease hostilities.
The town has changed hands several times during the conflict.
Some 100 aid workers - including 15 survivors of the helicopter crash - have now left the area.
There are also clashes in South Darfur, near Shearia.
Without aid workers in the region, details on casualties are sketchy but almost 30 soldiers and policemen were reportedly killed on Wednesday.
The BBC's Jonah Fisher in Khartoum says the international community has changed tack.
The government used to be generally blamed for the violence but now the US has condemned the rebels for launching their twin offensives.
Peace talks in Nigeria have been complicated by rows between different rebel groups and factions.
The new head of the African Union, Congo's Denis Sassou Nguesso, has meanwhile insisted that the AU should retain control of the peacekeeping operation in Darfur.
Some 7,000 AU troops are in the region but the mission is underfunded and some have suggested that the UN take control.
British MPs on Wednesday urged Prime Minister Tony Blair to support tougher action to stop the violence in Darfur.
"The United Nations can bring forces, but all of that should be to support the AU forces, under the command of the AU and its officers who are there," Mr Sassou told Reuters news agency.
The Darfur rebellion started in 2003, with groups saying the region's black African population was being ignored by the central government.
Pro-government Arab militias then launched reprisals against the civilian populations, forcing some two million to flee their homes.
Sudan's government has denied backing the militias and has accused Western nations, such as the US, of exaggerating the problems in Darfur for political reasons.