US forces say they have carried out no fresh air strikes in southern Somalia against Islamist fighters since Monday.
UN officials fear the air strikes could lead to an escalation of hostilities
Residents in Afmadow town, north of Kismayo, have described two attacks, whilst another was reported by Somalis in the coastal area of Ras Kamboni.
Reports suggest Ethiopian MiG fighters and helicopter gunships seen in the city of Kismayo may be involved.
There has been considerable criticism of the US after its first overt military action in Somalia since 1994.
The Pentagon confirmed that US aircraft targeted al-Qaeda suspects on Monday but has not said whether they met with success.
Washington has dismissed the international criticism, saying it was necessary to defend the US and the international community from further al-Qaeda attacks.
Somali officials say leading al-Qaeda suspect, Fazul Abdullah Mohammed, accused of masterminding the bomb attacks on US embassies in East Africa nine years ago, may be among those killed in the earlier raids.
A local Somali MP said 27 civilians died in recent air strikes near Afmadow.
Ethiopia's prime minister Meles Zenawi says several terror suspects have been either killed or captured in the strikes.
He told reporters Ethiopian forces had gone to the scene of Monday's US raid and collected the dead and wounded.
He denied the US hit civilians but said those killed "may have involved very senior Islamist court leaders".
The United Nations Security Council is set to meet to consider moves to send African peacekeepers into Somalia to help protect the transitional government.
The initiative was agreed before the Union of Islamic Courts' militia were ousted by Ethiopian-backed government forces.
They had taken control of much of central and southern Somalia over the past six months, before being routed from the capital, Mogadishu, and driven south.
The US has long said al-Qaeda suspects linked to the 1998 US embassy bombings in East Africa took refuge in Somalia. It also accuses the Islamists of having links to al-Qaeda - charges they deny.
The UK Foreign Office is currently investigating reports that Britons are among those killed in the fighting after Somali officials said they had found a variety of international passports on the bodies of dead Islamist fighters.
In other developments:
- Fazul Abdullah Mohammed's wife and the wife of Saleh Ali Saleh Nabhan, also wanted by the FBI for an attack in East Africa in 2002, have been arrested in Kenya after fleeing the coastal Somali town of Ras Kamboni, Kenyan intelligence sources say
- The interim government has called for all clan militia to assemble at designated points across the country to disarm, retrain and join the national army
- There has been a fresh attack on an Ethiopian vehicle in the capital, Mogadishu, following Tuesday's rocket attacks
- Health officials say fighting is preventing them confirming a possible spread of the deadly Rift Valley Fever from Kenya
Correspondents say the situation on the ground in southern Somalia remains unclear, with communications in the area poor.
The Islamist fighters are hiding in densely wooded areas close to the Kenyan border in the southern tip of Somalia.
Somalia's interim deputy prime minister, Hussein Aideed, said the US action was necessary precisely because of their location.
"This is [the] south of the country, and it is a no man's land... it is forest. It's not easy to move in with military vehicles," he told the BBC's Network Africa programme.
The BBC's Bashkas Jugsodaay who is between the Kenyan border and Doble town says dozens of people, mainly pastoralists, and their cattle were killed in air strikes on Tuesday evening near watering holes.
Eyewitnesses in two settlements between Doble and Afmadow say the attacks lasted for between 30 to 45 minutes.
Aid workers report that more 1,000 people have been wounded since fighting erupted in December. However, there is no reliable information on casualties in the current fighting in the remote south.