MOGADISHU, Somalia  Fierce fighting exploded in this capital city on Friday night and Saturday morning, and witnesses said at least 10 people had been killed in the past two days, possibly including a Somali-American who had joined the insurgents.

One battle began on Friday after soldiers from Somalia’s transitional government attacked an insurgent base with mortars and machine guns.

“Soon after breaking fast,” said Fatima Elmi, a Mogadishu resident, referring to the evening Ramadan holiday ritual, “we heard strange noises of weapons and we ran into a concrete building nearby.”

The government forces pushed back the insurgents, who belonged to an extremist Islamist group called the Shabab. But by Saturday morning, witnesses said, the Shabab had recaptured the territory and once again remained in firm control of most of Mogadishu.