Ethiopian troops carried out more attacks on rebels inside Eritrea on Saturday, a government source said, a day after its neighbour called for UN action over a similar incursion earlier in the week.
The attacks are the first on Eritrean soil that Ethiopia has admitted to since the end of a 1998-2000 war that killed 70,000 people and left a border dispute unresolved. Eritrea says there have been others.
"We've carried out further attacks on targets inside Eritrea. This time it's in the north section around Badme," a senior Ethiopian government official told Reuters on Saturday.
"We were once again successful. This strike was part of our plan to take proportional measures that included the (earlier)attacks in Eritrea's southeast." He did not specify who had been targeted in the latest attack.
On Thursday Ethiopia said it had raided three military bases inside Eritrea that it said were being using to train an Ethiopian rebel group it blames for killing five foreign tourists and kidnapping two others in its remote Afar region in January.
Eritrea responded by saying it would not be "entrapped" by the military incursion, signalling its determination to avert another conflict with its bitter foe, and it called on the United Nations to act against the aggression.
A spokesman for Ban Ki-moon said the UN chief urged both sides to exercise "maximum restraint" and "respect each other's territorial integrity."
The British government expressed concern about the earlier incursion into Eritrea, saying it risked undermining efforts to develop security and stability across the Horn of Africa.
A vicious row over the position of Eritrea and Ethiopia's shared border was not resolved at the end of the war.
The Hague-based Eritrea-Ethiopia Boundary Commission ruled in 2002 that the border village of Badme belonged to Eritrea. But the village remains in Ethiopia, Washington's main ally in the volatile Horn of Africa.