Islamic militias that seized control of much of southern Somalia have executed a man by firing squad, the first public execution since they took over in June.

The man killed Friday, was sentenced to death for murdering a man in a cell phone dispute. A spokesman for the Islamic courts said the execution will send a message that Islamic sharia law will be enforced.

Somalia has not had an effective government since 1991. A U.N. backed interim government was formed in 2004 but now controls only the town of Baidoa. Islamists seized the capital, Mogadishu, in June.

Somalia's interim government and the Islamists are attempting to work out a peace agreement as both try to expand their authority.

Talks have been deadlocked over the issue of a regional peacekeeping force in Somalia, which the Islamists strongly oppose.

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