''We were playing football when suddenly a boy pulled out a string. The string was tied to a box that had a landmine concealed in it,'' blast survivor Mohamed Deq, 11, told Reuters.
''The children started hitting the object and suddenly it exploded. It killed 5 children and wounded others. I was so shocked but survived.'' Eyewitness Abdirizaq Sheikh said the blast at a livestock market ''shook the earth'', wounding at least 10 children.
The incident is the latest in an escalating wave of violence in the lawless Horn of Africa nation.
In late June, a suspected bomb blast killed five women cleaners when one of them stumbled upon a device in garbage they were burning.
Asha Ibrahim lost her two sons in today's blast.
''They died in the hospital. They were among a group of children who picked up a bomb concealed in a box,'' Ibrahim told Reuters by telephone from Madina Hospital.
Separately, Somali government soldiers arrested a 14-year-old boy who they said threw a grenade at them as they patrolled the busy Bakara market in the city centre on a 'technical' -- a pickup truck mounted with anti-aircraft guns.
The blast injured two civilians.
''Troops chased the boy and caught him. He has been locked up,'' a senior police officer told Reuters.
JOINT OPERATION Somalia's interim government -- the 14th attempt to set up central rule in Somalia since the 1991 fall of a military dictator -- is struggling to impose authority in the country.
Late yesterday and early today, Ethiopian troops and government soldiers carried out a joint operation in and around Mogadishu's Bakara market to confiscate weapons.
''The aim of the operation is to improve the security of Mogadishu ahead of the upcoming national reconciliation conference and reduce the explosions that have increased in Mogadishu,'' police operations chief Yusuf Hussein Osman told Reuters.
Police displayed a cache of assault rifles, rocket-propelled grenades and a large pile of bullets to reporters today.
''We also plan to deploy 500 troops in Bakara market which is a hideout for those people who are behind the blasts,'' Osman said.
The reconciliation conference, seen as the last best chance for the government to boost its legitimacy and secure a workable peace is due on July 15, but many fear insecurity in the capital will force another delay.
Meanwhile, the UN World Food Programme today said a total of 62 of its trucks carrying 1,800 tonnes of food supplies into southern Somalia had crossed in from Kenya this week.
The Kenyan government had closed the border over security concerns, which WFP had complained was hampering food delivery.
Reuters RKM DB2137