A Somali MP has been assassinated, marking the fifth parliamentarian in the torn country to be killed this year.

Sheikh Aden Madeer, the chairman of the parliamentary finance committee, was shot when he left a mosque in the capital city of Mogadishu after Friday prayers, witnesses told the BBC

The Islamist militant group al-Shabab, an offshoot of al-Qaeda, told the BBC they carried out the assassination. Al-Shabab members advocate the Wahhabi version of Islam and battle the government in a similar fashion to that of al-Qaeda. 

According to lawmaker Siidow Abaadir in an interview with the state-run radio station, three assailants fired on Madeer and then fled. The Shabab's military operations spokesman Sheikh Abdiasis Abu Musab called lawmakers like Madeer "infidels," and added the attacks haven't ended.

The U.N. has condemned the murder in a statement from envoy Nicholas Kay:

The murder of MPs is an attempt to intimidate and undermine those working to build a better Somalia. Their killers will not achieve that objective.

I commend Somalia's MPs for their courage and dedication in the face of continued attacks against them. Urgent action is needed to bring the perpetrators to justice.

About 22,000 African Union troops are helping the government try to win back territory. Somalia is currently divided in control between four main groups: pro-government supported by Ethiopia, Islamists, pro-government administrations, and the African Union.