The U-N mission responsible for keeping peace along the contested border between Ethiopia and Eritrea is investigating a weekend firefight in which one Eritrean soldier was killed.

A spokeswoman for the 42 hundred-strong U-N Mission in Ethiopia and Eritrea, Gail Bindley Taylor Sainte, says Saturday's killing of an Eritrean militia man may not necessarily be related to last week's cancellation of the border demarcation exercise.

"I think this is a random incident. We are just looking at the situation on the ground to see what caused it before we can make that kind of statement."

She was reacting to concerns from observers that conflict between the two Horn of Africa countries might escalate because the long-standing border dispute failed to be resolved as scheduled.

A particularly strong warning came from the independent research center, International Crisis Group. In a report it released in September, the center warned that the two countries could go to war again unless the border marking is completed.

Last week, the independent Eritrea-Ethiopia Boundary Commission that was to have set up posts and other border signs to mark the one-thousand-kilometer border, announced it suspended the exercise indefinitely.

Ethiopia is reportedly upset with the commission's decision to include an area called Badme within Eritrea's border.

The exact location of the border was the cause of a brutal war between the two countries from 1998 to 2000, in which an estimated 70-thousand people died. As part of the peace deal signed in 2000, the commission was to set the markers along the agreed border.

Ms. Bindley Taylor Sainte says the Eritrean militia operating in a buffer area told the U-N mission that unknown soldiers widely reported to be Ethiopian soldiers fired on them, killing one Eritrean soldier.

She says the mission is still investigating the incident and is expected to complete its report shortly.