Seven Ethiopian Christians have been arrested and detained in the north-western town of Chagni on suspicion of praying against the government when they prayed against the devil's kingdom, according to World Watch Monitor (WWM).

A local source told WWM that the seven men, who are members of the Meserete Kiristos church, were followed and overheard by a local militia group when they went up a mountain to pray.

When the Christians prayed 'against Satan's power and kingdom', which WWM said is a common choice of words in certain evangelical churches in Ethiopia, the militia group accused them of referring to the government.

Although they have yet to be charged formally, the Christians were refused bail at a court hearing on January 2 and remain in custody. It is not clear when their next court appearance will be, WWM reported.

Ethiopia is ranked 29th on the newly released 2018 Open Doors World Watch List of the 50 countries where it is most difficult to live as a Christian.

Pressure on Christians there is judged to be 'very high' because of religious and ethnic tensions, combined with political and civil unrest.

Meanwhile, Ethiopia's northern Tigray State has been considering adopting a new law that would restrict Christian activities to within official church compounds, rendering illegal the activities of smaller churches that do not have official buildings and instead gather in private homes, WWM noted.

Pentecostal churches in rural areas also often face restrictions in a society dominated by the Ethiopian Orthodox Church (EOC).

WWM has reported regularly about attacks on Christians and the closure of churches in the country.

However, the latest census in 2007 showed that Christianity is still Ethiopia's main religion, with Christians making up some 63 per cent of the population.

The country is home to 'one of the fastest growing evangelical churches in the world', wrote the theologian Allan Anderson in 2014.