The BBC's Cathy Jenkins reports on the aftermath of the bombing raids

Reports from northern Ethiopia say at least 35 people - including 10 children - have been killed in an Eritrean air raid on the town of Mekele.

Earlier, Eritrean anti-aircraft guns shot down one Ethiopian plane during an attack on the airport in the capital, Asmara. There was another Ethiopian raid to the south-east of the city.

One man on an access road was killed and four people injured.

Ethiopia said the attacks were in retaliation for an earlier Eritrean air raid on Mekele, in which five people were wounded.

The UK ambassador to Ethiopia, Gordon Wetherell: Armed forces instructed to take all necessary measures

A foreign journalist who witnessed the bombing near the airport said two fighter jets were involved.

A BBC correspondent in Asmara says roads to the airport became jammed as jubilant Eritreans flocked to see the wreckage of the enemy jet.

The Eritrean Government had earlier accused Ethiopia of wanting all-out war.

Evacuation

Foreign nationals have begun leaving Asmara after gathering at consulates and embassies.

A plane organised by the US Government took nearly 200 people, mostly Americans, out of the region late in the day.

US nationals evacuate Asmara

But a flight being organised by the British Government failed to leave Cairo after the Eritrean government refused to give it landing permission.

A British official said they had tried for more than two hours to get clearance but eventually several dozen British nationals, who had waited all day to fly out, were asked to return in the morning.

The BBC correspondent said several Britons were still undecided about leaving with one man deciding to stay after he had bid farewell to his collegues at the University of Asmara.

Meanwhile, the Eritrean Foreign Minister, Haile Weltensae, speaking at the Organisation of African Unity meeting, said Ethiopia has given his government seven days to cut its diplomatic presence in Addis Ababa to three people, and to close two consulates.

Heavy fighting

Prior to the air raids the two sides had been fighting with heavy artillery, mortars and small arms across a broad valley in the mountainous Alitena region.

Both sides have blamed the other for the fighting

The Eritreans said the Ethiopians were forced back to what the Eritreans say is the international border.

Both sides have accused the other of launching the offensive, which caused thousands of refugees to flee.

The Eritrean Foreign Ministry described the Alitena clash as a dangerous escalation of a border dispute between the two countries, which until recently enjoyed friendly relations. It said this was the fourth attack by Ethiopia in less than two weeks.