NAIROBI, Aug 23 (Reuters) - Ethiopian soldiers are accused of burning homes, seizing livestock and killing civilians in its toughest crackdown yet on rebels in a remote, forgotten part of the vast Horn of Africa country.
Rights groups say abuses escalated in Ogaden when the government launched a campaign two months ago to root out separatist insurgents who attacked a Chinese-run oil exploration field in April, killing 74 people.
But Prime Minister Meles Zenawi -- facing armed if low-level opposition in most corners of Ethiopia -- shows no sign of ending his push against the Ogaden National Liberation Front whom he calls "terrorists" bankrolled by arch-foe Eritrea.
Shrugging off some pressure from the West which fears the conflict may further destabilise the Horn, Meles asserts his right to rid the region, bordering lawless Somalia, of the ONLF's "cold-blooded murderers".
"No stone will be left unturned," he has vowed.
With several thousand gunmen thought to be in their ranks, the ONLF says they want greater autonomy for their homeland, which may be rich in natural gas and oil.
Known for hit-and-run attacks on military targets, the ethnically Somali rebels often melt into villages across Ogaden's grassy plains when retaliation is threatened.
Few experts expect Meles, equipped with one of Africa's biggest armies, to waver from his hardline stance.
His campaign benefits from the remoteness of the area, which is largely cut off to aid workers and journalists, and the lack of leverage available to the West to stop it, they say.
"None of the rebel groups threatens the government, although the ONLF has been the most active," said one Western academic who follows the Horn but did not want to be quoted on Ogaden.
"Many of them are in the outlying hinterland regions and aren't close to central Ethiopia. They operate in a very remote area that Ethiopia could let burn."
The ONLF, which sprung up in 1984, has long traded on a deep sense of marginalisation felt by the Ogadenis against a central government -- dominated by former rebels from the northern Tigray province -- to fuel its rebellion.
It says it has the support of the mostly nomadic Ogadenis, who number anywhere between 4 and 10 million people.
But analysts say the ONLF is held back by the lack of a consistent political aim, with demands for total independence and inclusion in a "Greater Somalia" made at various times.
They say the group exploited a security gap that emerged when Ethiopian troops in Ogaden moved to bolster Somalia's interim government across the border.
Despite the rebels' allegations that a trade blockade is squeezing food supplies and causing starvation, the government may ride out any Western backlash.
"The Ethiopian government has proven to be quite capable of weathering international criticism," the academic said.
"There isn't much leverage the international community can use. Major donors don't want to suspend programmes and the United States needs an ally in its counter-terrorism war."
Moreover Addis Ababa ploughs significantly more money into Ogaden for roads and other services than it receives in taxes.
A crucial factor that may be driving Meles' crackdown is energy. Several oil and gas firms have shown interest in Ogaden including Malaysia's Petronas, China's Sinopec and India's GAIL.
Several experts on the region suspect energy explorers who signed deals with the government are putting pressure on Meles to ensure security in gun-infested Ogaden.
"What hit the government was that all the oil companies operating there left the region (after the April attack)," said another foreign analyst. "Now they are all in talks with the government about solving security, the political situation with the ONLF and making sure there's fair distribution of profits."
He said the government had hoped for a fast campaign. "They were probably hoping six months was enough before the focus on human rights gathered momentum."
Although the ONLF has been accused of targeting civilians and blamed for a spate of grenade bombings, its complaint of political inequity touches a nerve with many ethnic groups.
Critics say the government has failed to uphold Article 39 of the constitution, which espouses the unconditional right of "Every Nation, Nationality and People in Ethiopia" to self-determination, including secession.
The concept of ethnic federalism was meant to cement together a nation of 81 million people living in nine states, encompassing a myriad ethnic groups, scores of languages and three major religions.
But, Abdulkader Sulub Abdi, the Geneva-based international coordinator of the Ogaden Human Rights Committee, accused Meles of favouring his Tigrayan ethnic group since 1991 when he ousted Amharic military dictator Mengistu Haile Mariam.
"The Tigrayans and the Amharas before -- the highlanders -- see themselves as the elite with the God-given right to rule other people. They see themselves as the masters of the land."
"Meles' government and his policies are forcing people to join the rebels," Abdi told Reuters.