Somali Islamic Leader Surrenders in Kenya

But the Oromo region has also been the scene of droughts and other tribulations that have forced thousands of refugees across the border and into Somali cities, including Mogadishu.

"Whether a man has relations with those organizations or not, he will be arrested," Luqman said. "Because he is Oromo. They can't distinguish if he belongs to the movement or not. So that's the problem."

At one Oromo refugee camp, a sprawl of doorless houses with cardboard roofs, the people left were mostly old men, women and children. A leader there, Abdirahman Omar, 67, said that Ethiopian and Somali troops showed up after morning prayers Jan. 4 and arrested 12 Oromo refugees, including his son, Aden. All remain missing.

"He does not even speak the Oromo language," said Omar, who came to Somalia in 1979 and said his son is a math teacher. "He knows nothing about Ethiopia, let alone Ethiopian politics."

In another neighborhood, Kilometre Four, Habiba Dahir said that her husband, Abdijabar Isee, an Oromo, was arrested recently as he was walking down the street with a Somali friend.

The friend told her later that a plainclothes Somali policeman approached them and asked Abdijabar for his name, and that shortly afterward a pickup truck full of green-uniformed Somali police officers drove up, blindfolded her husband and threw him in the truck with another blindfolded man.

"At first we were told he was killed, but later we learned he is alive," said Dahir, who denied her husband was involved with any militant movement. "I can't say any more."

Special correspondent Mohamed Ibrahim in Mogadishu contributed to this report .