The United States denied reports on Wednesday that Washington had mounted a new offensive targeting al Qaeda suspects in Somalia on Wednesday.
Earlier, Somali officials reported at least four new U.S. air strikes in the south of the country, near the Kenyan border.
Wednesday's offensive came after an assault against a village where al Qaeda suspects were believed to be hiding two days earlier.
But officials in Washington, who confirmed Monday's raid, denied there are been fresh strikes.
U.S. government sources said Ethiopia, which ousted Islamist forces last month, had been behind the new strikes.
Ethiopian Prime Minister Meles Zenawi said there had been only one U.S. air attack and no civilian casualties.
The attacks are believed to have hit an area near Ras Kamboni, a coastal village close to Kenya where many Islamists are believed to be hiding after being pushed out by Ethiopian troops.
On Wednesday, Abdirizak Hassan, the Somali president's chief of staff said he believed the U.S. airstrikes in Somalia would continue.
"I know it happened yesterday, it will happen today and it will happen tomorrow," he told The Associated Press.
First offensive since 1993
The two days of airstrikes by U.S. forces were the first American offensives in the African country since 18 U.S. soldiers were killed here in 1993.
"What they're basically worried about in Somalia is the fact that the militias have just introduced Shariah law about six months ago. Somalia could become a haven for al Qaeda training and al Qaeda operatives so I think that's one of the reasons why the U.S. supported the Ethiopian army to take them out of Mogadishu," international security consultant Alan Bell told CTV's Canada AM.
The strike in southern Somalia on Monday killed between five and 10 people believed to be associated with al Qaeda, said U.S. officials, speaking on condition of anonymity.
The same day, Somali military commander Col. Shino Moalin Nur and witnesses said U.S. airstrikes were launched against Islamic extremists in Hayi, about 48 kilometres from Afmadow.
A Somali lawmaker said 31 civilians, including a newlywed couple, died in Tuesday's assault by two helicopters near Afmadow, a town in a forested area close to the Kenyan border. The report could not be independently confirmed.
At least one U.S. AC-130 gunship attacked a suspected al Qaeda training camp on a remote island at the southern tip, Nur claimed.
"Nobody can exactly explain what is going on inside these forested areas," the Somali commander told AP Tuesday.
"However, we are receiving reports that most of the Islamist fighters have died and the rest would be captured soon."
Pentagon spokesman Bryan Whitman said the assault was based on intelligence that led the Americans to believe they could target al Qaeda leaders.
In Washington, a U.S. official told AP it would be virtually unheard of for the United States to be involved in an operation of this size without "eyes on the ground."
Two senior Pentagon officials said they had heard of no plans to put any sizable contingent of Americans in Somalia.
But the officials said small teams of liaison officers were another matter.
The U.S. military said Tuesday that the aircraft carrier USS Dwight D. Eisenhower arrived off Somalia's coast and launched intelligence-gathering missions over Somalia. Another three American warships were also conducting anti-terror operations.
The Islamist fighters captured Somalia's capital Mogadishu in June, and by August controlled most of southern Somalia.
Ethiopia intervened on Dec. 24, and over 10 days drove the Islamist fighters to the south of Somalia, near the Kenyan border.
Suspect militant may be dead
Meanwhile, a suspected al Qaeda militant wanted for bombing U.S. embassies was killed in an American offensive in Somalia, an official has confirmed.
"I have received a report from the American side chronicling the targets and list of damage," said Hassan.
"One of the items they were claiming was that Fazul Abdullah Mohammed is dead," he said, a claim that if true, would mean the end of an eight-year hunt for a top target of Washington's war on terror.
But U.S. government officials, who spoke on condition of anonymity, told The Associated Press they had no reason to believe the suspect had been killed.
Mohammed, 32, allegedly planned the 1998 attacks on the U.S. embassies in Kenya and Tanzania that killed 225 people.
Washington holds the same cell responsible for the bombing of an Israeli-owned beach resort in Kenya, and an attack on an Israeli airliner in 2002.
Ten Kenyans and three Israelis were killed in the blast at the hotel, about 19 kilometres north of Mombasa.
Mohammed is believed to have been the main target of an American helicopter attack Monday afternoon on Badmadow island off southern Somalia.
The senior al Qaeda suspect was born in Comoros, an Indian Ocean archipelago-nation, and he is able to appear African, South Asian or Arab.
He was able to speak French, Arabic, Swahili and English.
He joined al Qaeda in Afghanistan and trained there with Osama bin Laden, according to the transcript of an FBI interrogation of a known associate.
He came to Kenya in the mid-1990s, married a local woman, became a citizen and started teaching at a religious school near Lamu, just 96 kilometres south of Ras Kamboni, Somalia, where one of the airstrikes took place Monday.
Taking refuge
Authorities believed he had been taking refuge in Somalia since the 2002 hotel attack.
In 2003, the CIA offered rewards to Somali warlords in return for capturing al Qaeda suspects.
At least two were captured, but Mohammed managed to evade the CIA with the help of Somali Islamic extremists.
He was briefly captured by Kenyan police for credit card fraud but he was not recognized as a terrorist suspect. He escaped the next day.
In Somalia, he was protected by members of Al-Ittihad al-Islami, an organization listed by the United States as a terrorist group linked to al Qaeda.
The U.S. accuses the Islamists in Somalia of having links to al Qaeda, but they deny those accusations.
Mounting criticism
U.S. warships have been trying to seize al Qaeda members believed to be fleeing Somalia by sea after Ethiopia's military stepped in to defend the country's interim government.
President Abdullahi Yusuf, head of the UN-backed transitional government, told journalists in Mogadishu that the U.S. "has a right to bombard terrorist suspects who attacked its embassies in Kenya and Tanzania."
But international criticism is mounting over Washington's intervention.
UN chief Ban Ki-moon expressed his regret on reported loss of civilian lives in the American offensive.
Italian Foreign Minister Massimo D'Alema said Rome opposed "unilateral initiatives that could spark new tensions in an area that is already very destabilized."
There are also fears the offensive would fuel anti-American sentiment and feed Islamist militancy in the largely Muslim country.
"The fact the U.S. had their own agenda to take out any al Qaeda influences in that part of the country, it could backfire," Bell said.
Many Somalis are already upset over the presence of troops from neighbouring Ethiopia, which has a large Christian population.
With files from The Associated Press
