MOGADISHU, Somalia -- Ethiopian jets pounded militia-held positions in southern Somalia, a sharp escalation yesterday of a conflict that diplomats fear could ignite a regional war.
Several hundred people have been killed over the past five days in fighting between Ethiopian forces and Somalia's Islamic militias.
Witnesses and officials said early morning strikes by Ethiopian military planes killed about 80 fighters and civilians and wounded 300 in the town of Baladweyne, which has been held by Somalia's Islamic Courts Union.
"The enemy launched full-scale war against Somalia," said Sheik Mohamoud Ibrahim Suley, an official of the Islamic courts. "The fighting has commenced, and it will not stop unless Addis Ababa stops the aggression."
Ethiopia's Prime Minister, Meles Zenawi, went on national television to say the country had been "forced to enter into war ... to blunt repeated attacks by Islamic courts terrorists and anti-Ethiopian elements they are supporting."
Ethiopia until now had acknowledged only sending several hundred military advisers to Somalia.
International diplomats warn that Somalia's worsening strife could ignite a full-scale war in the Horn of Africa, the region in the northeastern part of the continent that lies across the Red Sea and Gulf of Aden from Saudi Arabia and Yemen.
Somalia has been without a functioning government since 1991. The courts union, an alliance of Islamic religious leaders, seized control of Mogadishu and most of southern Somalia this summer and has been battling the weak transitional federal government for control of the rest of the country.
Ethiopia, a country whose leaders are fearful of an Islamic takeover in Somalia, is backing the transitional government. A third country in the region, Eritrea, has been backing the Islamic militias, and experts fear the conflict could draw in the volatile Horn of Africa region, which lies close to the Arabian peninsula and has seen a rise in Islamic extremism. A recent U.N. report said 10 nations have been illegally supplying arms and equipment to both sides in Somalia.
The U.S. government, which has worked with Ethiopia's military in the past, has worried that the courts union could provide sanctuary to Islamic radicals.
Yesterday's attack came one day after the Islamists' top security officer called on Muslims worldwide to come to the assistance of Somalia in what they are characterizing as a "holy war" against Ethiopia.
People living along Somalia's coast have reported seeing hundreds of foreign Muslims entering the country in answer to calls from the Islamic militia.
The Islamic group's often severe interpretation of Islam raises memories of Afghanistan's Taliban regime, which was ousted by a U.S.-led campaign for harboring Osama bin Laden. The U.S. says four al-Qaida leaders blamed for the 1998 bombings of U.S. embassies in Kenya and Tanzania have become leaders in Somalia's Islamic militia.
The Islamic movement drove secular Somali warlords supported by the U.S. out of the capital, Mogadishu, last summer and have seized most of the southern half of the country, which has not had an effective government since a longtime dictatorship was toppled in 1991.
In Washington, a State Department spokeswoman, Leslie Phillips, said yesterday that U.S. officials had seen the reports of escalated fighting in Somalia, "and we're following the situation closely."
She noted that in recent weeks, the U.S. has recognized that Ethiopia "has a security concern" in Somalia but has "urged all parties to act with restraint."
Eric Laroche, the United Nations Humanitarian Coordinator for Somalia, urged all sides to cease the hostilities in order to protect thousands of Somali refugees fleeing the violence.
"Indiscriminate shelling is a clear violation of the laws of war and has a devastating impact on the most vulnerable segments of the country," Laroche said. "People must have the option to move from areas of active conflict."
He added that the fighting is interfering with humanitarian efforts to assist nearly 500,000 victims of flooding in Somalia.
A witness in Baladweyne said some of yesterday's casualties were flood victims living at a displacement camp in the town.
A spokesman for the transitional government denied Ethiopian jets were involved in the attack, but Ethiopian officials confirmed the strike later yesterday.
"The Ethiopian government has taken self-defensive measures and started counter-attacking the aggressive extremist forces of the Islamic courts and foreign terrorist groups," Ethiopian Information Minister Berhan Hailu told Reuters.
He said the planes also struck targets in Dinsoor, Bandiradley and the town of Buur Hakaba.
Experts estimate Ethiopia has sent more than 8,000 soldiers to support the transitional government. Eritrea, which has battled Ethiopia for years, reportedly has sent 2,000 troops to assist the Islamists although the government has not acknowledged that.
In Mogadishu, Islamist supporters rioted, burned tires, stoned businesses and chanted anti-Ethiopian slogans.
"We will resort to all tactics, including suicide attacks, if the Ethiopians don't stop the occupation," said Hussen Hirre Abdi, 14, attending yesterday's protest.
Abukar Albadri and Edmund Sanders write for the Los Angeles Times. The Associated Press contributed to this article.