The volatile and mineral-rich region along the border with Uganda has been wracked by increasing violence involving rebel militias that has ensnared neighbouring countries.

Kenyan General Jeff Nyagah, who has led the East African Community (EAC) force drawing on troops from Burundi, Kenya, Uganda and South Sudan since November, said he was leaving the mission "due to aggravated threat to my safety."

"There was an attempt to intimidate my security at my former residence by deploying foreign military contractors (mercenaries) who placed monitoring devices," he said in a letter dated April 27 to the secretary general of the seven-nation bloc.

Nyagah said there was a "well-orchestrated and financed negative media campaign" targeting him that aimed to frustrate the efforts of the regional force.

Created last year to stop M23 rebels who seized swathes of territory in the eastern DRC, the EAC force is operating in areas that it says have been liberated from the militia.

But many locals are disappointed the force is not taking the fight directly to the rebels and say the M23 continues to operate with impunity.

Kenyan Major General Alphaxard Muthuri Kiugu is set to replace Nyagah has who been redeployed, according to changes announced Friday by the Kenya Defence Forces.

The total size of the EAC force is unclear.

The M23 first came to international prominence in 2012 when it captured Goma, before being driven out and going to ground.

But the Tutsi-led group emerged from dormancy in late 2021, arguing the government had ignored a promise to integrate its fighters into the army.

It then won a string of victories against the Congolese army and captured large chunks of North Kivu, triggering a humanitarian crisis.

More than 1.1 million people have fled its advance, according to UN's Office for the Coordination of Humanitarian Affairs (OCHA).

The DRC has repeatedly accused its neighbour Rwanda, an EAC member, of backing the rebels, a charge Kigali denies.

The United States and several other Western countries, as well as independent UN experts, have also concluded that Rwanda is backing the rebels.

Several regional initiatives intended to defuse the conflict have failed.