An Islamic fighter prepares to fire in a street littered with spent bullet casings during clashes with government soldiers in Mogadishu, Somalia, on Friday. (Mohamed Sheikh Nor/Associated Press)

Somali government forces in Mogadishu pounded Islamic militants with artillery and small arms fire on Friday, heavily damaging the heart of the capital and killing at least 13 people.

Government forces and militant Islamic rebels from the hardline al-Shabab and Hisbul-Islam groups who had taken control of parts of Mogadishu have been fighting for 10 days.

More than 100 people have been killed in that period, and over 45,000 are believed to be displaced.

Friday's surge in fighting has killed at least 13 people and wounded dozens, residents and an independent radio station said.

A journalist from radio station Shabelle was among those killed in Friday's skirmishes. Reuters, citing other residents and officials, put the death toll at at least 15.

Pictures graphic

Pictures of the fighting showed gunmen crouched behind the ruins of shell-pocked buildings and bodies lying in the streets. In one photo, a man clutches a wounded child to his chest in the back of a car, his shirt reddened with the blood streaming from the child's face. In another, a man's lower jaw has been torn away by a bullet or piece of shrapnel.

Shabelle editor Abdirahman Yusuf Al-Adala said a stray bullet killed journalist Abdirisaq Warsame Mohamed as he headed to work.

"This is a large military offensive against violent people," military spokesman Farhan Mahdi Mohamed told Agence France-Presse. "The government will sweep them out of the capital and the fighting will continue until that happens."

Lt. Yusuf Osman Dumal, the government's commander-in-chief, said the fighting began when Islamists attacked government positions, but residents said the government used the temporary respite to reinforce and re-equip the troops under its control and it appeared to be a planned government offensive.

Resident Abdi Haji said hundreds of government troops had attacked positions held by Islamist fighters in the south and north of the Somali capital. He said there was heavy shelling around Wadnaha road, which the government lost to Islamist fighters earlier this month. Wadnaha connects the north and south of the city and is one of the four major roads in Mogadishu.

Rebels deny losing territory

The government claimed it had taken back control of three areas of the capital — Tarbunka, Bakara and Howlwadag — since fighting began Friday. The rebels deny this account.

The government began the offensive because it said it was impossible to negotiate with the militants.

Somalia has been without an effective central government since 1991, when the former dictator Siad Barre was overthrown by warlords. A Western-backed transitional government was formed in 2004, but failed to assert control.

A unity government elected Sharif Sheikh Ahmed, considered a moderate, as president in January following UN-sponsored peace talks between the transitional government and Islamic militants.

Western governments fear Somalia may become a safe zone for terrorists, particularly since Osama bin Laden has declared his support for the domestic Islamists. The U.S. says al-Shabab is harbouring al-Qaeda-linked terrorists accused of blowing up the U.S. embassies in Kenya and Tanzania in 1998.

With files from The Associated Press