VSO's Andrew Waites at Heathrow on the anxious airlift

Western governments are going ahead with plans for a large scale overnight evacuation after the Ethiopian and Eritrean authorities reportedly agreed to a "window of opportunity" to stop exchanges in the spiralling conflict and allow planes to touch down.

The announcement came after Ethiopia's air force launched a second day of bombing raids on the Asmara military airport which is next to the civil airport

Forty-eight British aid workers arrived in London from Eritrea on Saturday but around 60 Britons are believed to be amongst hundreds of foreign nationals still stranded at the airport.

The VSO workers flew home on a charter flight via Frankfurt

The aid workers from the charity Voluntary Services Overseas were evacuated from the capital Asmara on Friday as the border dispute with Ethiopia escalated.

Flight 4644 from Heathrow to Frankfurt was the last leg of the volunteers' traumatic evacuation.

Many of the volunteers, who arrived at Heathrow, described their eye witness view of bombing raids and their fear for the safety of friends they had left behind.

VSO worker Debbie McGrath said: "In some ways life was perfectly normal, which has been the ironic thing about it.

Debbie McGrath of VSO believes many aid workers will return

"People were still watering their flowers and children were still going to school, but by Thursday when things escalated we decided we would have to leave."

Tensions between the two states prompted the Foreign Office to advise all British nationals in Eritrea to leave as soon as possible.

The VSO workers boarded an American chartered plane sent to take US nationals out of the capital last night and flew to Frankfurt.

Ms McGrath said: "The Eritreans are used to it. They have had 30 years of fighting. People stood out and watched for the MiGs as they went over and clapped when one was shot down.

"All our volunteers were in the city when the planes were targeting the airport. We could see the MiGs coming over and bombs coming out of them."

Reports have suggested that dozens of people had been killed and hundreds injured in air raids carried out by both countries.

Jenny Tinker, 26, from Reading, had been working as a teacher in the African state for two years.

Up to 60 Britons remain in Eritrea

She said: "We had seen tanks driving through the streets and we saw the MiGs bombing the airport, which was frightening.

"But there was a great spirit of camaraderie among the volunteers. People volunteered to get food and other things to help."

Jane Tremayne, 31, from Surrey, said: "We saw bombs dropping at the airport, which was really frightening.

"I am relieved to be out, but everyone remained calm. I was disappointed to leave and desperately concerned for those friends left behind."