According to aid agencies on Thursday, some Sudanese soldiers have even beaten back women searching for food and firewood.
There are at least 7000 refugees living in crude shelters on the Chadian side of the border town of Tine after being hounded out of Sudan's western Darfur.
Despite a 45-day truce which came into force on Sunday, civilians continue to bear the brunt of the conflict in Darfur, where two rebel groups have been battling government troops and marauding horse-riding militias.
Rebels from Sudan's western Darfur region said on Thursday they were unlikely to attend peace talks, accusing Khartoum of violating the four-day-old truce.
UN officials have described the violence in Darfur as ethnic cleansing and say some 110,000 refugees have fled to Chad.
However, data is several months old and many more refugees may be sheltering just across the border.
War and disease
Aid workers in Tine say they find children every day with severe malnutrition, though the number of people with wounds from bullets, shrapnel or mines appears to be dropping.
The few medics in the area are also battling a meningitis epidemic.
They believe there are another 5000-6000 refugees around the town of Bahai further north and say they must be taken to camps where they can be fed quickly.
The border town of Tine is all
One Red Cross co-ordinator, Abd al-Ilah Salih, says the main problem is water.
"People can't find any that they can drink. And there is no food. Only those who get to the camps get food."
The fifteen month-old conflict has pitted rebels against government forces and militia groups in the Darfur states that has spilled over into neighbouring Chad.
Since February 2003, two groups - the Sudan Liberation Army (SLA) and the Justice and Equality Movement (JEM) – have fought to push their political and economic agendas.
By July 2003, more than 110,000 Sudanese refugees had crossed the largely unguarded 1350-km border separating the two countries.
At the same time as playing mediator between Khartoum and the rebels, Chad has openly supplied troops to the Sudanese army in Darfur.