Ethiopian rebels said Friday they support the "speedy release" of two German tourists seized in a gunfight last week that left five Europeans dead, but accused Ethiopia of "sabotaging" talks.

"The two German nationals... are in our custody and safe," said the rebel Afar Revolutionary Democratic Unity Front (ARDUF) in a statement.

"Our efforts to set those German tourists free and send them home to their loved ones is brought to naught... by the stubbornness and inflexibility of Ethiopian officials."

The rebels did not give further details of why negotiations had stalled, but said they were in close contact with German government officials.

However, they warned that "any military engagement with ARDUF would... endanger the lives of the two German citizens."

The rebels also said they were ready to release two Ethiopians seized during the attack on the slopes of a famed volcano.

Addis Ababa blamed the region's worst attack on tourists in years on gunmen armed by arch-foe Eritrea, but Asmara has dismissed the claims as "ludicrous."

ARDUF, which has been fighting a low-level insurgency in the remote region to end what it says is "political marginalisation and economic deprivation" by Addis Ababa, claims to have no links to Eritrea.

At least five people were killed in the fighting -- two Germans, two Hungarians and one Austrian -- but the rebels say they also killed 16 Ethiopian soldiers.

Ethiopia has made no mention of losing any troops in the attack, which took place near the famed Erta Ale volcano in Ethiopia's sparsely populated Danakil desert, close to the tense border with Eritrea.

The area, which boasts spectacular moon-like landscapes and is known as the hottest place on earth, is popular among adventure travellers.

In 2007, ARDUF rebels seized five European tourists and eight Ethiopians. The Europeans were released after 12 days to the Eritrean government, while the Ethiopians were freed almost two months later.