They were part of a 1,700-strong group who had been bussed to the border by the Ethiopian authorities.

The 300 - comprising the elderly, sick, and disabled and very young children - were flown to Asmara from the port of Assab, close to where they had crossed the border at Bure.

They told the BBC that they had been harassed and stripped of their jobs and their property.

Most said they were happy to leave Ethiopia, but complained that they had been locked inside buses and denied food or water on their three-day journey to the border.

The region where they crossed the border is a low-lying desert where temperatures can reach more than 40C (100F).

Long voyage

The rest of the group is travelling by boat from Assab to Massawa - the harbour closest to Asmara. Assab is in a remote part of Eritrea with no road connections to the capital.

One eyewitness said that they had been packed onto two small freighter ships with no room to sit.

Many Eritreans have lived in Ethiopia for decades. They enjoyed the same rights as Ethiopian citizens until war broke out between the two countries last year.

Since then, many Eritreans have felt that their rights have been eroded, and are seeking to return to Eritrea.

The ICRC has been involved for several months in dialogue with the Ethiopian and Eritrean governments over the repatriation of Eritreans.

Security concerns

Last week, Asmara said it could not guarantee the security of people entering Eritrea via the border near Bure.

The Ethiopian Government responded by saying Eritrea was refusing to accept its own citizens.

The ICRC told the Ethiopian Government that in the absence of security guarantees from the Eritrean side, the repatriation would be contrary to article 36 of the fourth Geneva Convention, which concerns the safety of people in transit.

Ethiopia said the ICRC had fallen victim to Eritrean propaganda.