Five Europeans freed by kidnappers said Wednesday they were treated well and expressed gratitude to the governments of Eritrea and Ethiopia that led to their release.

However, in a statement issued by the British Foreign Office in London, the five diplomats and relatives said they were worried about the eight Ethiopians who were abducted with the group and who are still missing.

"We are very worried that the Ethiopians who were accompanying us are all still being held. We would not want anything to be said that might inadvertently jeopardize their safe release. Our foremost concern is that they should be released as soon as possible," the statement said.

The five said they spoke to their families and were looking forward to seeing them again but they needed time to take stock of what happened. They appealed to the media for privacy.

"We were treated well by our captors — physically we are all in good condition but obviously very tired," the statement said.

Fears were growing for the eight Ethiopians who were kidnapped with the group and who are still missing. The Ethiopian government called for their immediate release.

The Europeans were held captive for 13 days after being kidnapped while on a sightseeing tour near the disputed border with Eritrea. They were released Tuesday and taken to the British Embassy in Asmara, the Eritrean capital, where they were fed and given medical checkups.

A British Foreign Office Official, who spoke on condition of anonymity in line with ministry policy, said they were to leave Asmara shortly.

Michael Moore, the head of the British Council's Ethiopia office and the husband of one of the kidnapped tourists, said Wednesday he spoke briefly with his wife by phone.

"She sounded well and healthy. I am feeling very relieved and grateful for all the work that has been done so far," Moore told The Associated Press in Addis Ababa. He said they did not discuss details of her ordeal.

Eritrea, which has denied having anything to do with the kidnapping, blamed the Ethiopian rebel group Afar Revolutionary Democratic Unity Front. The group, established in the 1990s, aims to unite members of the Afar tribe in Ethiopia, Djibouti and Eritrea.

The claim could not be independently confirmed.

Relations between Ethiopia and Eritrea have been strained since Eritrea gained independence from the Addis Ababa government in 1993 following a 30-year guerrilla war. The two countries fought a two-year border war that ended in 2000.

The hostages were in the remote Afar region of northeastern Ethiopia when they were seized at gunpoint along with 13 Ethiopians. Their vehicles were later discovered abandoned, riddled with bullet holes and grenade shrapnel. Officials have said nobody was believed to have been in the cars at the time of the shooting.

Five of the Ethiopians had earlier been reported to have escaped or been released, but eight are still missing. The Ethiopian government, in a statement read on state-owned Ethiopian Television's evening news Tuesday, welcomed the release of the Europeans and expressed concern about the eight Ethiopians.

"These citizens should be released without any preconditions," the Information Ministry statement said.

The Europeans were identified as Peter Rudge, first secretary of the British Embassy in Addis Ababa; embassy worker Jonathan Ireland; Malcolm Smart and Frenchwoman Laure Beaufils of the Department for International Development; and Moore's wife, Rosanna Moore, an Anglo-Italian.

It was not clear where the tour group had been held. Ethiopian officials have said the hostages may have been taken by rebel gunmen and marched across the porous Ethiopian border into neighboring Eritrea. But Eritrea said Tuesday that the hostages only crossed into Eritrea immediately before being handed over to the embassy.