"The Ethiopian fighter planes did damage the runway" in the dawn raid, said Salome Tadasse.

"Various bombs hit their target," she added.

Sources in the Eritrean capital, Asmara, while confirming a raid had taken place, said the 12 bombs dropped by Antonov warplanes fell wide of the airport's runway.

A foreign journalist who saw the effects of the attack told AFP he had seen craters on adjacent sand and said the nearest hole was 200 metres (yards) from the runway.

Eritrean anti-aircraft weapons forced the Ethiopian planes to maintain a high altitude, Eritrean military sources told the journalist.

These guns "did not strike their target, their response was not significant," said Tadasse.

The bombing broke an undeclared truce in the border war between the two Horn of Africa neighbours.

The last fighting was reported, in the same sector, on Tuesday, when both sides reported attacks by Ethiopian fighter-bombers on an Eritrean military logistics centre near Assab. Artillery shelling was also reported.

Addis Ababa claimed its forces had destroyed weapons, ammunition, tanks and a water storage plant serving Assab.

Eritrea said the water plant had not been hit.

The two sides went to war over the ill-defined frontier in May last year.

The fighting petered out after about five weeks, but both sides continued to mass troops along the border, and the fighting reignited on February 6 after the failure of diplomatic efforts to resolve the contract.

A European Union team visited Addis Ababa and Asmara on Friday and Saturday, but reported that it had failed to win a ceasefire.

But an Ethiopian official said his country was "ready to observe a ceasefire."

Fighting intensified a week ago on the eastern front near Burie, in northeast Ethiopia, some 75 kilometers (45 miles) southeast of Assab.

On Wednesday, Addis Ababa said it would do all it could to "defend its national integrity."

Ethiopian warplanes have gone into action several times to bomb Eritrean sites on three fronts along the disputed border.

There have been many calls from abroad, including from the United States, for Ethiopia to halt the air strikes and for both sides to work towards a peaceful resolution of their dispute.

Ethiopian sources have stressed their aircraft would never target civilian areas, only military zones along the border.

On February 11, Addis Ababa called on Eritrea to evacuate civilians from combat zones.

For its part, Eritrea has said it reserves the right to respond in kind to air attacks.