Ethiopia and Eritrea are trading accusations over an incident in a disputed border area, with Ethiopia on Monday confirming its military had taken "proportional measures" against Eritrea in response to an attempted attack in the Tsorona area the day before.
"The attack heavily weakened Eritrean military's attacking capacity," Ethiopia's Communications Affairs Office said.
In a statement late Sunday, Eritrea's Information Ministry accused Ethiopian troops of carrying out attacks against Eritrean positions in the Tsorona Central Front.
The two countries have been in a stalemate since the end in 2000 of a border war in which tens of thousands of people were killed. The countries do not have diplomatic relations and have accused each other of training and deploying banned armed groups.
Relatives of people who live in the Tsorona area said their families were fleeing following heavy shelling early Sunday.
"My father lives in the area and told me by phone of heavy shelling in the area," Yared Tewolde said. "One heavy artillery shell has landed very close to a school, and this has scared many."
Charlotte King, an analyst with the Economist Intelligence Unit, said accusations of direct attacks by the two countries are relatively rare.
"It is also unusual for the Eritrean government to comment on violent outbreaks," she said, adding that Eritrea may be trying to divert international attention away from a U.N. commission's report released last week that accused the government of widespread crimes against humanity.
In New York, the spokesman for the U.N. chief, Stephane Dujarric, said Ban Ki-moon urged both sides to "exercise maximum restraint."
Ethiopian Prime Minister Hailemariam Desalegn recently told The Associated Press that his forces will act against Eritrea if Ethiopia is provoked. He called the Eritrean government an "arrogant and very stubborn regime."