The foes kicked off preliminary negotiations in the semi-autonomous region of Zanzibar, said the spokesman Odaa Tarbii.

"These initial talks are intended to establish a foundation for more extensive discussions in the very near future," he said, adding that Kenya and Norway were mediating.

"The focus at this point is confidence building and clarifying positions."

Ethiopia's government in Addis Ababa could not be reached for comment.

Prime Minister Abiy Ahmed had announced last week that talks with the OLA would begin on Tuesday, but gave no further details.

Tanzania's Foreign Minister Stergomena Tax told reporters on Tuesday that they had accepted a request to host the talks and some delegates had begun arriving.

The OLA, an armed insurgent movement from the country's Oromia region, has been fighting Addis Ababa since it split in 2018 with the historic Oromo Liberation Front (OLF) when it renounced armed struggle.

Since the OLA broke off and started fighting, a string of armed groups in Oromia have risen up claiming to be part of its cause, though are only loosely tied.

The OLA's strength, estimated at a few thousand men in 2018, has increased significantly in recent years, though observers believe it is insufficiently organised or well-armed to pose a real threat to the federal government.

Oromia surrounds Addis Ababa and is Ethiopia's largest and most populous region, and has suffered ethnic massacres in recent years carried out by unknown groups.

The OLA has been repeatedly accused by Abiy's government of being responsible for these massacres, which it denies.

The government is accused of waging an indiscriminate crackdown that has fuelled Oromo resentment against the central government.