Investigators were facing an increasingly desperate race against time yesterday to find five Britons kidnapped in the remote Danakil desert of northeastern Ethiopia.

The three men and two women, all of whom are connected to the British Embassy in Addis Ababa, are entering their sixth day held hostage in a region where food, water and medicines are all but impossible to find.

Their kidnappers have yet to make contact with either the Ethiopian or British governments. The region is known for banditry and is also the centre of a separatist struggle by the Afar people. Six days after the abduction, there are still no clues about the identity or motives of the kidnappers.

The Afar separatists receive support from Eritrea, which disputes the border region with Ethiopia.

Zeamanuel Legesse, the police commissioner of Tigray province, said that he had dispatched additional men to help the search in the neighbouring Afar province as time began to run out.

He said that Europeans would find it next to impossible to cope with temperatures that reach 50C (122F).

“It is so very difficult to move around in that desert, and if you stand still you will melt,” he said in Mekele, the regional capital.

“It is so remote that it is difficult to get information, so we are sending as many people as we can to the border region.”

The five Britons were staying in the tiny village of Hamedelah, about 500 miles (800km) from Addis Ababa, when they were snatched by unknown assailants.

The gunmen used grenades to disable their vehicles after rounding up their hostages in the early hours of Thursday morning.

Several pairs of hiking boots were among the personal items left in the vehicles, suggesting that the kidnap victims would have been poorly equipped to cope with days spent in the Ethiopian desert.

The land here sinks to 100 metres below sea level. A desiccating wind cuts across a scorched landscape of volcanic rock where nothing grows.

Even the explorer Sir Wilfred Thesiger, no stranger to extremes of climate and terrain, described the vast Afar region as a “veritable land of death — as much for its people’s fondness for guns as its blistering temperatures”.

Tony Hickey, a tour operator, who supplied the missing group with a cook and guide, said that survival was possible.

“It’s going to be tough, but there are places where water is available,” he said.

“At the end of the day they are with people who know how to survive there.”

Meanwhile, the UN mission given the task of monitoring a buffer zone along the border between Ethiopia and Eritrea offered its help to the search effort.

“The mission stands ready to assist with medical and logistical support, if and when the need arises,” Musi Khumalo, the force spokeswoman, told reporters in Asmara, the Eritrean capital.

Commander Legesse, in common with other Ethiopian officials, pointed the finger squarely at the Eritrean Government, saying that he believed its soldiers to be responsible for the kidnapping.

The claims have been denied by Eritrea.

It is understood that British Foreign and Commonwealth Office investigators based in Mekele have largely dismissed any Eritrean involvement along with rumours that the attackers were linked with the recently defeated Islamic courts in Somalia or al-Qaeda.

Instead, attention is now focusing on the packs of Afar bandits that have harassed tourists in the past.

“There are plenty of smoke-screens going up — with al-Qaeda and the Eritreans — but if I was a betting man I would put money on it being down to local gangs or Afar separatists,” a Western diplomatic source familiar with the region said.

Bandits operate in the Afar region, where separatists started a low-level rebellion in the early 1990s, and travellers are advised to use armed guards.

The Afar rebels kidnapped nine Italian tourists in 1995 but later released them unharmed.

Several hundred tourists visit the area to see the Danakil Depression, known for its salt mines and active volcanoes.

Who has taken the travellers?

Rebels

The most likely scenario (Richard Beeston, Diplomatic Editor, writes). Afar rebels are known to operate in this area and visitors are advised to travel with armed protection. The separatist movement was started in the early 1990s, calling for an Afar state on territory straddling Ethiopia, Eritrea and Djibouti

Eritrea

Ethiopian witnesses have directly accused uniformed Eritrean forces of abducting the British diplomats. Eritreans do launch raids across the disputed border, where a brief but bloody war was fought in 1998. It is possible that the Britons fell victim to the continued border tensions

Bandits

The Afar region is remote, wild and tribal. It is possible that bandits, who are known to operate in the area, kidnapped the British tourists to demand a ransom for their freedom. The theory has been discredited because the kidnappers left behind valuable items belonging to their hostages

Al-Qaeda

One unlikely theory is that an al-Qaeda cell may have perpetrated the attack. While al-Qaeda would like to abduct British diplomats, it would be very difficult for a force of foreign jihadis to infiltrate the area and carry out the abduction without local support. There is no evidence of al-Qaeda operations in Afar

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