Meles Zenawi, Ethiopia's prime minister, also said there had been only one US air attack with no civilian casualties.
Meles, speaking in Addis Ababa, said: "There was only one strike. That strike was against what they called the target of opportunity. I believe they did not miss the target."
Meles said the strike had killed eight fighters and that five others had been captured. He could not confirm rumours that specific al-Qaeda members had been killed.
Meles said: "The remains will be transported for tests, and until this is done, I cannot confirm."
In Cairo, Ahmed Ben Hilli, the Arab League's assistant secretary-general, said on Wednesday: "We demand that these strikes, which now target civilians and led to the killing of many innocent victims, be stopped.
"There was no UN Security Council authorisation for the US forces to hit Somali areas."
Ben Hilli also criticised the interim Somali government for backing the air attacks. "We'd hoped they'd care about the sovereignty of their country ... instead of calling for foreign intervention," he said.
Abdullahi Yusuf, Somalia's president, has said the air attacks were justified because they were mounted against al-Qaeda fighters.
Ahmed Aboul Gheit, Egypt's foreign minister, also criticised the air attacks and called on the Somali government to resume talks with the Islamic courts fighters.
Yusuf said on Monday that there would be no negotiations with the fighters.
Meles said Ethiopia wanted to pull out its troops as soon as possible and make way for African peacekeepers.
He said that so far no Ethiopian soldier had been killed or wounded in Mogadishu, the Somali capital.
Meles dismissed the view of some analysts that Somalia may experience an Iraq-style breakdown.
He said: "Analysts prefer to equate Somalia's situation in the direction of Iraq and Afghanistan. Every little incident is considered by them as a repeat of Iraq syndrome.
"Those who are seeking out such signals will seek out in vain because the situation in Somalia is different."