After being previously dubbed a "terrorist group," the rebel Ogaden National Liberation Front (ONLF) signed a peace deal with Ethiopia's government, officials announced on Monday.

The agreement brings an end to a 34-year insurgency in eastern Ethiopia's Somali Region State, also known as Ogaden. The ONLF has been fighting for the rights of ethnic Somalis living in the eastern state since 1984, including proposing secession.

"The Ethiopian government and ONLF delegations held productive discussions and reached a historic deal that allows the ONLF to undertake a peaceful political struggle in Ethiopia," Ethiopia's foreign ministry said.

The two sides will also now form a committee to discuss the root causes of the conflict, reported Reuters news agency, citing the agreement.

The Ethiopian government and ONLF delegations traveled to Eritrea's capital Asmara to hammer out the details of the deal and signed it on Sunday.

The recent thaw of ties between Ethiopia and former rival Eritrea has also helped transform Eritrea from one of the ONLF's main sponsors to a mediator between Ethiopia and the rebel group.

Clashes in oil-rich region

For years, ONLF rebels and Ethiopian troops have clashed in the eastern Somali regional state, which is thought to contain vast oil and gas deposits. One Chinese firm has been developing two gas fields in the region since 2013.

ONLF became internationally known in April 2007 when the group launched a deadly raid on a Chinese-run oil field. The attack killed 65 Ethiopians and nine Chinese nationals.

In response, the Ethiopian government launched a massive counterinsurgency campaign, with rights groups accusing security forces of widespread abuses, including rape, torture and murder.

Ethiopian Prime Minister Abiy Ahmed, who took office in April, has condemned the actions of security forces and said the situation was similar to state terrorism.

In July, Ethiopia's parliament took ONLF off the country's terror list, which prompted the group to declare an indefinite ceasefire a month later.

The peace deal was part of Abiy's efforts to reform Ethiopia, including reconciling with various opposition groups and working to forge peace with Eritrea.

rs/msh (AFP, Reuters, epd)