At least 12 people have died in a bomb attack in Somalia targeting Somali and Ethiopian troops in a busy market in the southern city of Baidoa, witnesses and officials have said.
The attack on Monday was the deadliest since Ethiopian and Somali troops captured Baidoa, about 250 km to the southwest of Mogadishu, from al-Qaeda-linked al-Shabab fighters in February.
Al-Shabab claimed responsibility for Monday's attack.
"We planted a remotely controlled bomb in Baidoa market. We targeted the Ethiopian and the Somali troops. About three of them died," Sheikh Abdiasis Abu Musab, spokesman for al-Shabab's military operations, told Reuters.
Musab said government soldiers had killed a number of civilians after opening fire following the blast but the regional governor has denied the accusation.
It was the second blast in the country in a week.
Witnesses said the explosion happened outside a butcher shop.
"As we shopped we suddenly heard a blast. I counted 10 dead civilians and over 30 others injured," Shukri Hussein, a mother of five, told reporters from Baidoa market.
"Most of the casualties were in front of the butchery inside the main market. All the casualties were civilians save a soldier who was slightly injured," she said, adding that the explosive was hidden in a female shopper's plastic bag.
She said the soldiers surrounded the market after the blast, shooting in the air.
Ali Aden, a nurse at Baidoa hospital, said the faicility received 35 wounded civilians.
Abdifatah Ibrahim Mohamed, the Bay region governor, told Reuters from Baidoa, said at least 12 civilians were killed and more than 30 wounded.
Ethiopia sent troops into Somalia last year to open another front against al-Shabab after Kenya deployed soldiers in the south.
On Thursday, the African Union's AMISOM force deployed 100 soldiers to the country's third biggest city and a former rebel stronghold in the south that served as a key recruitment and training centre until it fell to Ethiopian forces.
Last week, a female suicide bomber killed six people, including two top sports officials, in the theatre near the presidential palace in Mogadishu.