MOGADISHU: Islamic insurgents and government forces pounded each other with mortar rounds in overnight battles in Somalia's capital, killing at least 17 people, witnesses said Thursday.

The overnight fighting raises the death toll of Wednesday's fighting to at least 34, making it the worst single day's fighting in the capital, Mogadishu, since mid-May.

Ali Muse, of one of Mogadishu's ambulance services, said they had delivered more than 100 wounded to hospitals. Muse said the wounded included children, women and elderly people.

As the two sides battled for control of a police station in northern Mogadishu, some of the ensuing heavy shelling hit people emerging from Wednesday evening prayers at a mosque in the area, said Mohamud Daban Turyare, a resident in the area.

Another resident, Halima Gedi, described the scene as "horrific," saying walls nearby were bloodstained.

Elsewhere, in southern Mogadishu, the insurgents briefly attacked government soldiers and African Union peacekeepers on a road they frequently use. Abdi Haji, a shopkeeper, said the soldiers and peacekeepers then shelled a nearby residential area, killing five people in Bakara market.

Information Minister Farhan Ali Mohamed denied the government targeted residential areas, adding government forces were only defending themselves from attack.

A spokesman for one of the insurgent groups, Hassan Mahdi, said they did not attack any government positions but were defending themselves. Mahdi said once the insurgents repulsed the government forces then the government side started shelling residential areas.

Neither spokesman gave any casualty figures.

Mogadishu does not have any clearly defined battlegrounds and both sides' forces are located close to residential areas.

Islamic insurgents have been trying to topple the weak, Western-backed government for more than two years. There was a surge of violence in May, during which almost 200 people were killed.

The U.N. says the conflict has displaced more than 122,000 people. Though in recent weeks there has only been sporadic fighting, Mogadishu residents have continued to flee their homes, fearing more battles will occur.

Somalia has had no effective central government since 1991 when warlords overthrew a longtime dictator and then plunged the country into anarchy and chaos. The lawlessness on land also has allowed piracy to thrive off the country's coast, making Somalia the world's worst piracy hotspot.