Ethiopia may be on the brink of “a civil war”, according to experts who have spoken on the decision of the country’s prime minister, Abiy Ahmed, to order a military attack in response to hostile forces who attacked an army base in the north of the country on Wednesday.

The semi-autonomous northern state of Tigray, administered by the Tigray People’s Liberation Front (TPLF), is a tensed part of the country where the ruling party insists Addis Ababa has no compelling authority. The north of the country also holds the bulk of Ethiopia’s military installation, a situation that resulted from the 1998 war with northern neighbor Eritrea.

Speaking on Wednesday, Prime Minister Ahmed said TPLF had”crossed the red line” with the federal army “that has been protecting the people of Tigray for more than twenty years”. Ahmed also said Tigray now regards the Ethiopian army as “a foreign army”.

A statement from the Office of the Prime Minister also said the federal government had “maintained a policy of extreme patience and caution” in the face of “months of continued provocation and incite for violence by TPLF”. But now, the federal government is on the offensive, launching attacks on TPLF in certain areas.

These attacks are expected to continue on Thursday.

The BBC also reports electricity, telephone and internet services in Tigray have been cut. Ethiopia’s parliament has also proposed deliberating on a motion that seeks to characterize the TPLF as a terrorist organization.

But a professor of democracy at the University of Birmingham, Nic Cheeseman, warned that “Ethiopia could come apart at the seams” if the government engages the TPLF in open conflict. A few other ethnic groups in the country are currently pushing to secede from Africa’s second-most populous country.

Cheeseman added that what has emerged in the country “looks a lot like the start of civil war in Ethiopia”.

The Tigray ethnic group constitutes only about 5% of the country’s population but is probably the richest. Tigray is represented by TPLF, which used to be led by former Prime Minister Meles Zenawi.

The TPLF backed out of a governing coalition headed by the current prime minister over disagreements with Ahmed. These disagreements have since devolved into violent tensions.