A Somali radio station says government forces have opened fire on its headquarters after surrounding the building for the second time in four days.

Journalists for Shabelle radio in Mogadishu say troops fired shots at the station Tuesday, sending employees ducking inside for cover.

It was not immediately clear why the forces had surrounded the building.

Government soldiers raided the Shabelle headquarters on Saturday, briefly detaining at least 16 employees. The troops accused the journalists of attacking them with grenades, a charge the station denies.

The government has closed down the station more than once in the past, accusing it of inaccurate reporting.

Mogadishu has been plagued by violence on almost a daily basis since January, shortly after the government and Ethiopian backers ousted a rival Islamist movement from power.

Battles between Islamist insurgents and pro-government forces have killed thousands and prompted more than 100,000 others to flee the city.

The violence has complicated the Somali government's effort to assert authority across the war-ravaged Horn of Africa country.

The country has not had a stable central government since warlords ousted dictator Mohamed Siad Barre in 1991.

Some information for this report was provided by AFP, AP and Reuters.