At least 14 people are reported to have been killed in a mortar attack on a mosque in the Somali capital Mogadishu, BBC reported.
In total 64 people are now thought to have died in recent fighting between Islamists and government forces.
The mortar shell struck at the gate of the mosque, a worshipper was quoted as saying by the AFP agency.
The interim government has been fighting hardline Islamist groups in long-running violence which has killed thousands since 2006.
"The mortar shell struck at the gate of the mosque. I counted about 14 people who died instantly and 10 others were wounded," Hassan Abdifatah was quoted by AFP.
Another worshipper, Mumin Haji Yusuf, said: "I was inside the mosque when I heard a heavy explosion and shrapnel was flying everywhere killing many people."
Radical Islamist guerrillas such as al-Shabab group have sworn to topple the fragile and more moderate government led by Sheikh Sharif Sheikh Ahmed.
At least 50 people are thought to have died in gun battles between the rival factions since Thursday, when clashes erupted in a northern area of the city.
The BBC's Africa editor Richard Hamilton said the fighting has been some of the fiercest seen in Mogadishu in recent years.
Somalia, a nation of about eight million people, has experienced almost constant civil conflict since the collapse of its central government in January 1991.