Somalia has been wracked by violence since it first spiralled into civil war in 1991 [AFP]

A Somali legislator has been shot dead in Mogadishu, witnesses and politicians say.

Adan Bule Mohamed died after he was shot several times in the head and shoulder in front of his house in the Dharkinley neighbourhood in the south of the capital, they said.

There was no immediate information on the possible motive for Wednesday's attack, but some locals blamed clan armed fighters.

"Two men armed with AK47 -rifles shot the lawmaker dead in front of his house," resident Ali Aden, who witnessed the shooting, told the Reuters news agency.

"I believe it was the clan militia who occupied his own house by force for years," he said, adding that Bule had ordered
the security forces to evict the fighters.

A day earlier, at least two people were killed in a series of grenade attacks in the city, Reuters said.

Al-Shabab, an armed Islamist group trying to overthrow the government, claimed to have killed 15 government soldiers in four separate attacks.

The group said Tuesday's grenades were "just an introduction".

"We are planning more serious attacks inside the capital, Mogadishu," Abdiasis Abu Musab, an al-Shabab spokesman, told Reuters.

The group pulled most of their fighters out of Mogadishu, epicentre of their almost five-year campaign, in August amid reports of internal divisions and funding shortages.

The UN-backed government of President Sharif Ahmed has fought al-Shabab for four years and is protected by more than 9,000 African Union troops.

Somalia has been wracked by violence since 1991, when it first spiralled into civil war.