Fighting in Mogadishu has killed at least 75 people and wounded more than 100, according to medical workers.
Radical Islamic militiamen will observe a ceasefire in response to pleas from civilians hit by the violence and members of civil society organisations, Islamic Court Union chairman Sheikh Sharif Sheikh Ahmed said.
However, the Sheikh’s secular rivals are suspicious of the plan and leaders are planning to discuss whether to accept the ceasefire offer.
"The Islamists have ran out of ammunition, so they want to get breathing space for mobilisation and rearming their militia," said Hussein Gutaale, spokesman of the secular militias.
Medical workers in five hospitals have confirmed that at least 75 people have been killed since fighting began on Sunday and more than 100 others have been wounded, according to a joint statement.
Militia commanders, witnesses and hospital officials had said earlier that the fighting killed at least 84 people - 22 on Tuesdsay, nine others overnight, 35 on Monday and 18 on Sunday.
Most of the victims in the most recent fighting were civilians caught in the crossfire, including a five-month old baby who was shot in the back, said Shariif Dahir Guure, a nurse at the Shifo Hospital, one of four hospitals that treated most of the wounded.
Somalia has had no effective central government since 1991, when warlords ousted longtime dictator Mohamed Siad Barre and then turned on each other.
The nation of an estimated eight million people was carved into a patchwork of anarchic, clan-based fiefdoms. A UN-backed transitional government has based itself in the central city of Baidoa, but as yet has failed to assert itself elsewhere.