Ethiopia said Wednesday that four of the tourists killed in the northeast of the country were Europeans and the fifth an Australian, and blamed arch-foe Eritrea for backing their attackers.

"Terrorist groups trained and armed by the Eritrean government crossed the border and attacked them and the assailants have gone back," government spokesman Bereket Simon told AFP.

Unknown attackers killed the five foreign tourists in Ethiopia's northeastern Afar region, state television reported.

The foreigners were killed on Monday in the remote region bordering Eritrea, Ethiopian Television said, citing the defence ministry.

The report added that some of the foreigners were wounded and taken to hospital by government forces in the region, but it did not say how many.

The tourists were in a group, and according to other sources, some were missing.

The Afar region, an inhospitable scrubland and desert with shallow salty lakes and chains of volcanoes, is reputed to be one of the hottest places on earth. It also known for hominid fossil finds.

A French tourist disappeared in the region in 2004 leaving behind no trace apart from a rucksack.

In 2007, a group of European nationals were kidnapped in the region, but later released by the rebel group that captured them.

Ethiopia, which often accuses its arch-foe Eritrea of backing rebels fighting the Addis Ababa regime, accused Eritrea of supporting the group behind the 2007 kidnapping.

Ethiopia and Eritrea fought a bitter territorial war between 1998 and 2000 and are still deeply at odds over their border.