A senior official in an influential faction of Ethiopia's ruling coalition on Monday accused Prime Minister Abiy Ahmed of ethnic profiling in an anti-corruption drive that has seen scores arrested.
Debretsion Gebremichael, chairman of the Tigray People's Liberation Front (TPLF), said the arrests of more than 60 senior military and intelligence officers in recent weeks was an attack on ethnic Tigrayans, a group that has long held disproportionate power in government and the security services.
"The arrests... targeting individuals accused of corruption and human rights has veered from course and is being used to bring Tigrayan people to their knees," Mr Debretsion claimed.
"We do not compromise on the issue of rule of law -- all of us should be accountable for our actions -- but the mass arrests should not be used as a cover for political aims," he warned.
The TPLF was a founding member of the long-ruling Ethiopian People's Revolutionary Democratic Front (EPRDF) in which Tigrayans have traditionally held the reins of power, despite accounting for only around six percent of the population.
But the appointment of Abiy, an Oromo, in April and his breakneck implementation of reforms has loosened the Tigrayan grip on government, stirring resentment in some quarters.
Mr Debretsion claimed to discern "a hand of a foreign country" in the arrests, without naming the state he was referring to.
Among those so far arrested are a former deputy spy chief and the former head of the military-owned Metals and Engineering Corporation (METEC).
Ethiopia's attorney-general said last week that unnamed members of the security agencies were involved in a grenade attack that killed two people at a rally attended by Mr Abiy in June.