Islamic radicals carried out their second public execution in less than a month Friday amid fears of increasing extremist violence in Somalia.

Mahad Osman Ugas, 23, was executed by a six-man firing squad as several thousand people watched. A jury convicted him of killing a businessman while trying to steal the man's cell phone.

"Our son was killed unjustly," said Sultan Ali Sultan Ahmed, the elder of the executed man's local clan, who had wanted to try to pay blood money for the life of Ugas. "We appealed against the sentence but the court rejected it."

Top Islamic leader Sheikh Sharif Sheikh Ahmed said the execution was required under Islamic law.

"We have given the families of both sides a chance to solve the matter on their own but they couldn't so we carried out the execution."

CountryWatch: Somalia

The Islamic group's strict and often severe interpretation of Islam raises memories of Afghanistan's Taliban, which was ousted by a U.S.-led campaign for harboring Usama bin Laden and Al Qaeda fighters. Many residents credit the courts with bringing a semblance of order, but Somalia remains chaotic and violent.

An Italian nun was shot and killed on Sept. 17. A day later, the president of Somalia's interim government survived an assassination attempt when a suicide car bomb exploded outside the parliament.

Islamic leaders have denied responsibility for both attacks.

Days after the attacks on the nun and the president, the U.N. pulled international staff out of central and southern Somalia, saying its employees had received death threats. Aid workers, speaking on condition of anonymity because of the sensitive nature of the subject, said the threats came from Islamic extremists.

Somalia has not had an effective national government since 1991, when warlords overthrew dictator Mohamed Siad Barre and then turned on one another, throwing the country into anarchy.

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The government was formed in 2004 with U.N. help in hopes of restoring order after years of lawlessness. But the government never asserted much authority. The Islamic movement — which began in the 1990s — seized the capital, Mogadishu, after fierce battles with secular warlords in June and now controls much of the country's south.

The government controls just one town, Baidoa, 150 miles northwest of the capital.