The Ethiopian government accused Eritrean forces of attacking a military post at Erde Mattios in Tigray province early on Wednesday.

An Ethiopian government spokeswoman said the post is close to the front-line area, where the border conflict began last month.

Known by Eritrea as Badme and by Ethiopia as Badame, the area is a rocky 400 sq kilometre (155 sq mile) triangle of land claimed by both sides along the western border.

No details of the casualties were immediately available and there is no independent confirmation of the attack.

With renewed fighting on Tuesday further west at Zalambessa, the former close friends are now battling on two fronts.

The BBC correspondent in Eritrea says conditions on the Eritrean side have become much more difficult for fighting after the first rains of winter fell a week ago.

At the heart of the dispute in this area is a river which Ethiopia claims is the international border, but Eritrea says is well within Eritrean territory.

After the rains, the river turns from a dry bed to a fast-flowing stream, making it more difficult to use one particular route to resupply the Eritrean troops on the other side.

Calls for peace

Tony Lloyd: "I repeat an urgent call to both parties to agree a formal ceasefire" (15")

There have been calls for an end to the fighting by the Organisation of African Unity (OAU), the United Nations Secretary-General Kofi Annan, the United States and the United Kingdom.

Heads of state attending an OAU summit in Burkina Faso have decided to send a delegation to Ethiopia and Eritrea, headed by the new OAU chairman, President Blaise Compaore of Burkina Faso.

The British government has urged Ethiopia and Eritrea to work with the United States and Rwandan negotiators to resolve their border conflict.

Britain currently holds the presidency of the European Union and the Foreign Secretary Robin Cook has, on behalf of the union, urged restraint on both sides.

Offer of direct talks

On Monday, Eritrea appealed for direct talks with Ethiopia, to try to end the border conflict.

The Ethiopian government says it is still in agreement with an American-Rwandan peace plan which involves troop withdrawal, the restoration of the Ethiopian administration and a border demarcation commission.

But government officials in Addis Abeba say there can be no talks while areas of Ethiopia are under occupation.

Eritrea gained independence from Ethiopia after a referendum in 1993.