BBC- - The International Red Cross has urged warring parties in Somalia to protect civilians amid escalating fighting.
Thousands of Somalis are fleeing clashes between Islamist fighters and Ethiopian troops in what the Red Cross calls the worst fighting in years.
There were unconfirmed reports early on Monday of Ethiopian fighter jets attacking Mogadishu airport.
Ethiopia backs Somalia's transitional government, and is attacking the Union of Islamic Courts (UIC) on four fronts.
On Sunday Ethiopia admitted for the first time that its troops are fighting in Somalia.
PM Meles Zenawi said Ethiopia was forced to defend its sovereignty against "terrorists" and anti-Ethiopians.
The UIC, which has seized control of much of southern and central Somalia, says Ethiopian troops have been fighting alongside government forces for months.
Aid agencies say the fighting is putting further pressure on what is already a weak support system in the country.
Fighting between the transitional government and forces loyal to the UIC now stretches over 400km (250 miles).
Speaking on Sunday, Mr Meles defended the Ethiopian operation:
"We are not trying to set up a government for Somalia, nor do we have an intention to meddle in Somalia internal affairs. We have only been forced by the circumstances.
"We want to end this war urgently and we hope that Ethiopian people stand by the defence forces."
Speaking in Addis Ababa, the Somali ambassador, Abdikarin Farah, who represents the transitional government, said it was still ready to negotiate with the UIC.
"We are not the people who are pushing the war; we are not the people who are advancing. We are only defending ourselves - that's it. But still the negotiation, it's open and we are ready to have some kind of ceasefire."
Ethiopia says its forces have killed hundreds of Islamists, but Ibrahim Hassan Addow, foreign secretary for the UIC, told the BBC the Ethiopians were lying and that his forces were holding their own.
Air strikes and shelling were reported in border areas. Eyewitnesses said Ethiopian fighters bombarded the UIC-held town of Beledweyne near the border, on the fifth day of renewed fighting.
The Islamist group - which controls most of the south, including the capital, Mogadishu - on Saturday appealed for foreign fighters to join its troops in a "holy war" against Ethiopia.
The UN estimates that at least 8,000 Ethiopian troops may be in the country, while rival Eritrea is said to have deployed some 2,000 troops in support of the Islamic group.
A Saudi aggression fighter jet targeted a citizen's car driving in Fara area of Kutaf district in Saada province overnight, killing the driver and injuring his friend, a security official said on Monday.
Scores of Saudi enemy soldiers were killed and injured on Sunday when the army and popular forces repelled a Saudi military attempt to sneak into Shurfah site in the border province of Najran, a military official said.
The operation was accomplished successfully against the Saudi
Saudi aggression warplanes have launched more than 49 airstrikes over the past hours on several residential areas across Yemen, a security official said on Sunday.
The airstrikes targeted the areas of Malahiz and Husama in Dhahir district, and areas Thuban, Masahif and Sdad in Bakim district of northern Saada province.