While the generalised shelling and gunfire seen across the city in recent days had stopped on Monday, a single blast followed by some gunfire rocked the Kilometre Four area of south Mogadishu around 8am (0500 GMT), a Reuters witness said.
Military sources later said a landmine had gone off as a convoy including the government's chief of military staff was driving past.
But there were no injuries, and it was unclear if it was a targeted attack or a mine left from previous days.
As Somalis stepped cautiously out on to the streets to check on damage, stock up on food, and see friends or family, some began burying the corpses virtually where they found them.
Several hundred people are believed to have been killed in the fighting.
With rotting bodies still lying in the streets on Monday, it was impossible to calculate an exact death toll from what the International Committee of the Red Cross called Mogadishu's worst fighting in more than 15 years.
"The situation is Somalia has gone from bad to worse after the intervention of Ethiopian troops"
Abed, Kumasi, Ghana
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Somali reporters have seen scores of corpses, Ethiopia says it has killed 200 insurgents, and residents say they believe several hundred people, mainly civilians, have died.
Diplomatic efforts to halt the violence were being stepped up this week.
The International Contact Group on Somalia, which includes the United States, European and African nations, was due to meet in Cairo.
While Addis Ababa seems determined to finish off the rebels, many experts say the attacks could have the opposite effect, turning Somalis further against their Christian-led neighbour, or drawing in foreign Muslim jihadists.
Despite the fighting, Somalia's interim government remains confident a reconciliation meeting of elders, politicians and former warlords planned for April 16 will go ahead in the city.
The administration is the 14th attempt to restore central rule in Somalia since 1991, when the Horn of Africa nation slid into anarchy after dictator Mohamed Siad Barre was overthrown.