Who are Ethiopia's ONLF rebels?

Dec 11 (Reuters) - Ethiopia's Ogaden National Liberation Front (ONLF) launched attacks on government positions last month and are warning international oil companies not to explore for their region's potential deposits.

Here are some key facts about the ONLF:

* The Ogaden National Liberation Front (ONLF) is the most active of the country's rebel groups. It was formed in 1984 amid a resurgence of separatist sentiment in the Ogaden region, which is near Ethiopia's border with Somalia.

* In April 2007 the rebels attacked an oilfield run by Sinopec, Asia's biggest refiner and China's second largest oil and gas producer. Sinopec then pulled out of the Ogaden. Most of Ethiopia's oil and gas exploration activities have centred on the vast desert province. The rebels want firms to stay away.

* Ethiopia's Somali region, of which the Ogaden is a part, is mainly populated by Muslim Somali-speakers. The area has its own identity, doing most of its trade with Somaliland, Somalia and the Middle East, rather than the rest of Ethiopia.

* The ONLF dominated the Somalia region's government from 1991 until 1994. But the regional parliament passed a resolution in 1994 to hold a referendum on independence for the Ogaden and was then dissolved by the government.

* The group says its goal remains a referendum on independence for the region.

* The rebels have employed a strategy of hit-and-run attacks, often using grenades and landmines before melting back into the region's largely nomadic population.

* The Ethiopian government says the ONLF is trained and funded by Horn of Africa rival Eritrea in an effort to destabilize Ethiopia. Regional analysts agree

Mahdi, who rarely speaks to the media, told Reuters the rebels wanted a referendum on independence for the region's Muslim, ethnic Somali people. And he dismissed claims the ONLF was helping Somalia's Islamist al Shabaab rebels, who are waging a violent war against that country's U.N.-backed government.

"The ONLF, as a matter of policy and principle, does not and will not collaborate with extremist organisations," he said. "This is a struggle for self-determination."

Analysts say that, along with its potential mineral wealth, the desert region's location between Somalia and Addis Ababa makes the Ethiopian government determined to hold on to it after a long history of hostilities with its neighbour.

The government says the ONLF has no popular support and is funded by rival Eritrea in an attempt to destabilise Ethiopia.

Bereket Simon, the Ethiopian government's head of information, told Reuters the rebels had regrouped since 2007, but called November's attacks a "last desperate act".

Locals said the rebels were believed to be planning more assaults.

The rebels and the government routinely accuse each other of terrorising the local population, burning villages and murdering and raping civilians.

The ONLF accuses government forces of stopping food aid and commercial supplies from reaching their strongholds, putting thousands of drought-affliced civilians at risk of starvation.

Ambassador Cousin's visit was carefully managed by the United Nations and the Ethiopian government. Her convoy rarely left main roads, and she said saw no evidence of the ONLF charges.