Somalis near the border with Ethiopia say that country's troops have crossed over, raising speculation of another battle with the militant Islamists closing in on Somalia's government.
Militant Islamists have the moderate government surrounded in Mogadishu. If they took over, it would be a devastating blow to US counter-terrorism and anti-piracy efforts in East Africa.
Monday, the government and an opposition bloc signed a UN-brokered peace deal. But Tuesday, Islamist hard-liners said they would continue to fight.