The hostages appeared tired, but in good health

Seventeen foreign tourists who were held in the Sahara desert for more than two months have been flown back to Europe after being rescued.

The 10 Austrians, six Germans and a Swede - who officials said were physically unharmed - arrived back on Wednesday evening aboard special flights from the Algerian capital.

However, their respective governments have been refusing to reveal details of how their ordeal ended because of concern this might compromise the safety of 15 other tourists who are still missing.

A plane full of the Austrian tourists arrived in Salzburg, where relatives of those kidnapped waited on the tarmac before embracing them as they walked down the plane steps.

Meanwhile, German and Swedish captives and German Deputy Foreign Minister Juergen Chrobog, as well as a doctor and psychologist, arrived at a military base in Cologne, Germany.

One hostage gave a victory sign as he walked down the steps, while others appeared to be tired, leaning on the handrail but nevertheless in good health, the Associated Press news agency reported.

'Dawn raid'

A total of 32 adventure tourists were travelling without guides in a number of groups using four-wheel drive vehicles and motorbikes when they disappeared between mid-February and mid-March.

The Algerian army said on Wednesday it had rescued 17 of the group who, it said, had been kidnapped by an Islamic group allegedly linked to Osama Bin Laden's al-Qaeda network.

It said the foreigners had been freed unharmed after an assault by government forces on a hideout of the Salafist Group for Preaching and Combat (GSPC) on Tuesday, and that all the necessary precautions had been taken to avoid putting the lives of the remaining captives at risk.

The Algerian daily newspaper El Watan claims that nine kidnappers were killed in the dawn raid near the Sahara desert town of Tamanrasset, 1,900 kilometres (1,200 miles) south of Algiers.

And Salzburg governor Franz Schausberger told Austrian press and radio that he had information that the hostages were freed in a raid by an Algerian task force.

"In my view, this positive end is basically the result of the relatives' capability for endurance, but also of the excellent cooperation between the Austrian and the Algerian authorities," he told Radio Salzburg.

'Precarious' situation

However concerns remain for the rest of the foreign hostages still missing.

SALAFIST GROUP FOR PREACHING AND COMBAT Wants Islamic state in Algeria One of most hardline groups fighting government On US list of "terrorist groups" Grew out of Armed Islamic Group (GIA) around 1998 Profile: Algeria's Salafist group

"We expect everything will be done so that the lives of the European hostages still detained in the Algerian Sahara will not be endangered," a German Government spokesman told reporters.

German Interior Minister Otto Schily, speaking on German television, described the situation of the remaining hostages as "precarious", but added that there was hope that the 10 Germans would soon be free.

These developments come a day after the German Foreign Minister, Joschka Fischer, spoke of hostage-takers for the first time.

Mr Fischer visited Algeria on Monday, where he held talks with President Abdelaziz Bouteflika.

He told reporters that he had urged Algerian officials "not to use force to try to free the hostages".

Asked who might be behind the kidnappings, he said: "I can't and don't want to answer this question, in the interest of the family and friends of the missing people."