The search for the five Britons missing in the Danakil Desert is rapidly becoming a race against time.

Just one day in the blistering, dry heat is an ordeal. There are no trees to offer respite from the huge Ethiopian sun and without litres and litres of water, dehydration is only ever a matter of an hour or so away.

The missing tourists are now into their fifth day. There has been no news of their whereabouts.

Bits and pieces left behind at the scene of their kidnapping in the tiny village of Hamedelah suggest they weren't allowed time to get themselves prepared for days in the desert.

Several pairs of boots were left in one of the 4x4s that had brought them to this inhospitable environment.

So where are they now?

Villagers taken with the Britons and then released say they were being marched towards the Eritrean border, about a three-hour walk away. That makes the search infinitely more complicated than if they had stayed in Ethiopia.

The two countries maintain a high state of alert over their disputed border. Full and frank co-operation in the hunt for the missing five seems inconceivable with the region balanced continually on the brink of war.

Initial reports suggested Eritrean soldiers were responsible for taking the Britons and that remains a possibility.

But why then did the local militias entrusted with guarding Hamedelah not raise the alarm as foreigners rode into the village?

Why did they not use their AK-47s or give chase?

Why did the guesthouse owner where the Britons were staying insist on accompanying his clients into the starlit desert night?

Why were a number of villagers taken and then released?

It is possible that the real culprits are nothing more exotic than local bandits or rebels known to the people of Hamedelah.

But whoever is responsible, they may be alarmed at the international attention the kidnapping has attracted.

Ethiopia is abuzz with reports of SAS operations being planned and practised, which raises another frightening prospect.

If the kidnappers realise they have bitten off more than they can chew in snatching staff from the British embassy in Addis Ababa, then they may simply be abandoned to make their own way to safety.

In a region where temperatures reach 50C and which is almost devoid of human settlements, that could prove to be their greatest challenge yet.

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