More than 30 followers of the Ethiopian Orthodox Church have been killed over the last several days by security forces in the Oromia region amidst tension sparked by a breakaway faction, the privately owned Borkena news site reports.
The circumstances of the trouble are unclear, but local news site Addis Standard, quoting the police, reports that 19 people were killed during a confrontation with security forces.
The church's leadership had called on followers to dress in black and observe three days of fasting and prayers after three archbishops in Oromia region dissented and announced the formation of a "new holy synod".
This new synod went ahead and anointed 26 bishops in Oromia.
More than 20 priests and those supporting the position of the main church were arrested in Oromia region's Arsi Negele Zone, privately owned Addis Maleda online TV reported on Monday.
The main church has sued the Oromia regional government, the federal and Oromia police commissions to stop the setting up of a separate holy synod.
A federal court is expected to make a ruling on Wednesday over the matter.
The Ethiopian Orthodox Church has also accused the government of "meddling" in its internal affairs after Prime Minister Abiy Ahmed instructed his cabinet ministers to keep out of the matter, saying the church should solve the problem through its internal mechanisms.
The church had wanted the government to take its side.
There is anxiety about the future of one of the world's oldest churches, as both the holy synod and the breakaway group have called for separate rallies in the capital, Addis Ababa, next Sunday.