Security forces in Ethiopia's Oromia regional state have killed a large number of Oromo Liberation Army (OLA) rebel members, the Government Communication Service announced.

In a statement on Saturday, the Minister of State Communications, Legesse Tulu, said an anti-insurgency operation is underway to eliminate the OLA, which the government declared a terrorist group.

Read: Ethiopia's Oromo rebel leader predicts victory 'very soon'

Many “members of the militant group have been killed in the operation,” he said, without revealing the exact number of casualties.

The minister said the military campaign is being carried out in the western and eastern parts of Welega, western and eastern Guji, north, east and west of Shoa, as well as in Borona zone bordering Kenya.

An Oromo opposition official, who spoke to The EastAfrican, confirmed that there is an ongoing military operation in parts of Oromia region.

“The Ethiopian army is carrying out drone strikes to conduct targeted killings in many areas,” said the official, who spoke on condition of anonymity.

“However, several innocent civilians are also victims of the ongoing warfare.”

A few days ago, an Oromo opposition political party, the Oromo Federalist Congress (OFC), said in a statement that a “secret war” was taking place in the Oromia region and many civilians had been killed as a result.

The party called for an independent international inquiry into the alleged “mass killings”.

OFC said the Ethiopian government security forces are conducting a campaign led by the principle of “drying the sea to catch fish.”

“Killing civilians, burning homes, looting and destroying property; imprisoning and torturing, sometimes killing parents on alleged affiliation of their children with OLA, has become commonplace,” reads an OFC statement seen by The EastAfrican.

“More recently, drone and helicopter strikes have been carried out by government forces in connection with this campaign.”

The party added that “indiscriminate airstrikes” carried out in recent days has resulted in the death of more than 30 civilians and caused severe property damages and displacement of a large population.

OFC alleged that more than 280 civilians have been massacred since April 16 under the ongoing joint military operation.

“Failure to protect innocent civilians is tantamount to failure of the System,” the party said, further calling for an independent international inquiry into the alleged mass killings.

The Ethiopian government has denied the allegations and said the campaign was aimed at curbing killings, displacement and destruction of properties caused by OLA.

A new report by UNOCHA said that violence in western Oromia has displaced half a million civilians, with intensified hostilities leading to the closure of hundreds of schools and health facilities,

“In 2022, partners have come under increased security threats, including two shooting incidents, various harassment, temporary detention, and forceful commandeering of their vehicles,” OCHA said.