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.
- The Ethiopian government is itself partly made up of former rebel groups. Prime Minister Meles Zenawi came to power in 1991 when rebels led by him and others overthrew a communist regime. He has said his government will not commit war crimes in the Ogaden as they know what it is to be rebels.
- The separatist cause has been fuelled by widespread resentment at the region's low level of development. Until Chinese engineers arrived in 2006, the entire region had just over 30 km (20 miles) of tarmac road.
(Reporting by Barry Malone, editing by Paul Taylor)
- Reuters - Thomson Reuters Foundation
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