Since April, a militant Somali group, calling itself the Mujahideen Youth Movement, has taken responsibility for numerous Iraq-style guerrilla attacks against the leaders of Somalia's interim government and the Ethiopian troops protecting them. As VOA correspondent Alisha Ryu in Mogadishu explains in this special report, the Mujahideen Youth Movement appears to be the more potent successor of the radical military wing of the Islamic Courts Union, called the Shabbab.
In interviews with Shabbab members in January, shortly after the defeat of the Islamic Courts Union by Ethiopia-led troops, VOA had reported that the Shabbab, loosely meaning youth in Arabic, claimed several thousand members with at least some degree of military and terrorist training.
Its founder and leader, Adan Hashi Ayro, is believed to have been trained by al-Qaida in Afghanistan and for years had provided shelter in Somalia for at least three al-Qaida operatives wanted in connection with the 1998 U.S. embassy bombings in East Africa.
Ayro was the military chief of the Islamic Courts Union, when he fled Mogadishu in late December with a guard force of several hundred Shabbab fighters. The remaining fighters, who were not killed in the Ethiopian offensive against the Islamists, melted back into society in Mogadishu and other Somali towns and cities.
Through extensive interviews with dozens of people in Mogadishu and elsewhere in Somalia, VOA has learned that in February, a new Shabbab leader emerged in Mogadishu and began re-grouping former fighters and recruiting new ones to conduct hit-and-run attacks against Ethiopian and government troops in the capital.
Somalis interviewed by VOA would not reveal the identity of the new Shabbab leader, but they say unlike Ayro, who lived in Afghanistan in the 1990s and belongs to the Ayr sub-clan of the locally-dominant Hawiye tribe, the new leader is not a Hawiye and has never received terrorist training outside Somalia.
On May 22, al-Qaida named Ayro as its leader in Somalia, but Ayro's whereabouts is not known and it is not clear whether he is still a part of the Shabbab-Mujahideen leadership.
A local Mujahideen Youth Movement commander, who reportedly leads a team of 30 guerrilla fighters in Mogadishu, tells VOA that reports of U.S. backing for the Ethiopian invasion of Somalia infuriated many religious people here, who believed that - in his words - Christian invaders branded leaders of the Islamic Courts Union as terrorists to justify a war against Islam in Somalia.
"The Americans are fighting to eliminate from the globe the Muslim faith," he said. "They do not want Muslims to exercise their belief. That is what we believe. The occupation of Ethiopian troops in Somalia caused much [more] anger than you can imagine."
Hawiye clan members also became angry over what it believed were deliberate moves by former factional leaders in the interim leadership to settle old scores with the Hawiye and several of its sub-clans.
Ethiopia's unflinching support of the interim leaders convinced many Hawiyes that Ethiopia was not interested in bringing peace to the country. Disgruntled Hawiye militiamen soon joined the anti-government, anti-Ethiopian fight, alongside the Shabbab.
By mid-March, a deadly insurgency was raging in Mogadishu. Ethiopian and government troops responded with a large-scale crackdown in the capital.
As the military operation continued for nearly a month, an increasing number of residents began complaining about the Ethiopians firing tanks and weapons indiscriminately in residential neighborhoods. The Ethiopians and the Somali government accused the insurgents of using civilians as human shields.
The civilian death toll climbed and hundreds of thousands of people fled the city.
During this period, businessmen and residents, especially from the Ayr sub-clan of Adan Hashi Ayro, also began complaining bitterly, accusing government troops of using the threat of terrorism as an excuse to loot property and to silence critics of the government through arrests and detentions.
On March 23, a prominent al-Qaida leader, Abu Yahya al-Libi, issued a message on an Internet website, encouraging the use of suicide and roadside bombings against Ethiopian troops and the government in Somalia.
There is no evidence of a direct link, but in early April, the Shabbab is said to have arranged a meeting in Mogadishu with several Somali Islamic organizations, including al-Itihaad al-Islamiya, a long-established radical group the United States believes has links to al-Qaida.
Shortly thereafter, the name Mujahideen Youth Movement began appearing on extremist Islamic websites on the Internet, claiming responsibility for numerous Iraq-style suicide and roadside attacks, assassinations, and attempted assassinations in various parts of Somalia.
Somali interim Prime Minister Ali Mohamed Gedi, whom the Mujahideen has targeted twice for assassination in the past month, says his government is certain that the Mujahideen Youth Movement, like the Shabbab, is an extension of the al-Qaida terrorist network.
"We believe that terrorist elements are responsible for what is happening in this country," he said. "They are linked with international terrorism and al-Qaida. Somali nationals have been tainted by foreigners, have been motivated by foreigners. They are tools for the al-Qaida network."
If so, there are worrying signs that popular support for the Mujahideen is rising quickly in the capital and in other parts of Somalia.
Mogadishu resident Mohamed Nur says the widely-held perception that the country is being led by a clannish, closed-minded government, propped up by a foreign occupying force, is fueling support for the radical Islamists.
"Compared to government soldiers, people like insurgents," he said. "I am not saying 100 percent, but most of the people see insurgents as freedom fighters. The problem with the government is that they might want to secure peace, but on the other hand, they are creating more problems. They are creating more insecurity."
Operating in teams of five to 30 fighters, the Mujahideen Youth Movement has extended its presence well beyond the capital to Lower and Middle Shabelle regions, and Lower Juba Valley, among others.
The fighters are said to be receiving food, shelter, and other assistance from individuals and sub-clans opposed to the government, as well as from unknown foreign donors, possibly in Libya and Egypt.