The United Nations' envoy to Somalia is strongly condemning the murder of a well-known Somali comedian apparently for his sarcastic remarks about al-Shebab Islamic extremists.

Abdi Jeylani Malaq, known as Marshale, was shot dead outside his home in Mogadishu Tuesday. No one has claimed responsibility.

U.N. envoy Augustine Mahiga calls the killing “simply unacceptable.” He calls on Somali authorities to do all that is necessary to carry out a full and independent investigation.

The human rights group Amnesty International says it is shocked at another death of a Somali media figure, but also at what it calls the inaction of Somali authorities. It says Marshale is the eighth media member to be targeted for death in Somalia since December.

Marshale appeared on Somali radio and television. Many of his routines were aimed at trying to stop young Somalis from joining the extremists. He had received numerous death threats.