The two helicopter gunships took off late in the morning, blades slashing the air as they banked over Nayala airport to head off for another day on the killing grounds of Darfur.
The Russian-built Hines began their military mission just after a flight had arrived from Britain loaded with aid for villagers fleeing the murders, mutilations and rapes of the Sudanese region, which is experiencing what the United Nations has described as the "world's worst humanitarian crisis''.
Loaded ammunition trucks were seen heading for the airport just before the gunships took off. Aid workers say they frequently find fragments of weapons launched from the air outside Nayala.
The refugees tell the same story: first comes the attack from the air, and then the Janjaweed militia arrive to mop up. Women are raped in front of their sons, their fathers, their husbands. Families are chained together and burnt alive.
Ibrahim Salim Musa and his family arrived in Nayala from a village outside Ta'asha in the north-east three weeks ago. Their home, and those of their neighbours, was burnt down, he said, by the Janjaweed. About 10 people, including two children, were killed. The rest fled.
Mr Musa, 37, his wife Safeera and their four children aged between three and 12 live in a room in a half-built house with shattered windows. They share with four other families. Mr Musa said of the attack: "We had heard there would be trouble. These men were boasting they were going to get rid of the Zurghas (a pejorative term for blacks)so we were prepared to get out quickly.
"It was very late; the children were asleep. We heard a lot of shouting and then rifle-firing. They were mostly on foot, but there were trucks and some had horses. They were dressed in white; we knew who they were.
"We ran. We were lucky because our house was towards the end of the village. We looked out from the trees; homes were burning. Later we heard who died.''
In another room, an old woman in a black chador sat rocking, locked in her private misery. Another woman shouted out: "They killed her sons, her brother. They want to kill us all. They are devils, just devils.''
Her father hushed her; another family member took her away. He turned: "They attacked us because we are from the Zaghawa [a tribe] and they say we support the rebels. But that is wrong. We are just poor people.''
The helicopters are flown by members of the Sudanese military, which is accused of helping the Arab Janjaweed militia in its war, purportedly against the rebel African Sudan Liberation Army, but one waged indiscriminately against African civilians. The conflict has claimed up to 30,000 lives and driven a million from their homes.
Families like the Musas are now hugely vulnerable. Deaths from cholera, severe diarrhoea and malnutrition are rising fast. With torrential rain about to start, and aid having to be delivered through churned mud, international agencies predict an even more terrible catastrophe in the making.
Yesterday's flight from Britain was organised by the Department for International Development. Organisations such as Oxfam, Save the Children, World Vision and UN World Food Programme are working flat out to stem the tide of disaster.
They face enormous problems. The humanitarian effort is surpassed by the systematic efforts at ethnic cleansing and fighting in the regions around the city, sometimes within 10 miles of it. Maps on the walls of the agencies have slashes of red for roads considered too dangerous to travel on.
For the refugees, relative safety lies in proximity to Nayala. The population of the Kalma camp to the south-east has swollen to 50,000. To the north-west, Kass has 42,000. Slightly further off, Mershing has 27,000 and Duma and Merwash together total 11,000.
In these camps, men and
women, the elderly and the very young, are struggling to survive in squalor. There is disease, and the makeshift shelters are places of violence and sexual abuse. Rape victims who sought safety are raped again.
The Sudanese government, which has 30 days to disarm the militia under a watered-down UN resolution, says that accusations of collusion with the Janjaweed are false. It has warned that mooted attempts to send in Western - including British - forces on a humanitarian mission would lead to a quagmire, another Iraq.
There is, however, little sign that the government has begun disarming the militia. It is following a policy of dispersing the refugees and sending them back to their villages which have been, more often than not, ransacked or resettled with Arabs.
Just six days ago a group was sent back to their homes from Nayala by the Sudanese authorities. Eleven miles outside the city they were ambushed by the Janjaweed. Those not killed or too severely injured fled back to the city.
The refugees in Nayala live in fear. They huddle on the sidewalks of the dusty orange tracks of the city, shrinking against the walls as uniformed men carrying Kalashnikovs strut by. The refugees we spoke to repeatedly pleaded that they should not be thrown out until the villages had been made safe. Asking them to leave now, they said, would be sending them to their deaths.
The two sides are predominantly Muslim and there is a history of intermarriage. The "Arab" refugees in Nayala look very much like their "African" counterparts. The Africans, however, talk about threats from the Arabs - teaching the Zurghas a lesson and taking the land for "good Sudanese Arabs''.
Captain Rex Adzagha of the Ghanaian army is part of an African Indian monitoring team, the advance guard of a force due to expand to 2,000. At present there are too few of them to do anything but prepare reports.
How were they coping? Have they seen much violence, burning? He shrugs: "We are doing all we can. Yes, I have seen lots. I have seen burnings. All you have to do is to drive around here to see all that."