By Abdi Sheikh and Feisal Omar

MOGADISHU (Reuters) - At least 12 people died in a bomb attack on Monday that targeted Somali and Ethiopian troops in a busy market in the southern city of Baidoa, witnesses and officials said.

It was the second blast in the country in barely a week. Last week, a female suicide bomber killed six people, including two top sports officials, in the theatre near the presidential palace in Mogadishu.

(Abdi Sheikh and Feisal Omar in Mogadishu; Additional reporting by Mohamed Ahmed in Nairobi; Editing by George Obulutsa and Jon Boyle)