Two children have been killed and at least five people were injured after a series of attacks by insurgents in the Somali capital, Mogadishu.
The pupils died along with an elderly man after a roadside bomb exploded as students walked to school in the city's northern Gupta district.
Meanwhile several people were injured in two separate grenade attacks against government forces and police.
Peace talks have failed to quell continuing violence in the city.
The insurgents "plant bombs among the civilians and leave it behind. It is a barbaric decision," police spokesman Colonel Abdi Wahid told the Associated Press news agency.
One of the victims' classmates, Abdullahi Mohamed Warsame, told Agence France-Presse: "I spoke to one of them by phone this morning... what did they do to deserve this?"
Grenade attacks were mounted firstly against security forces searching for weapons in Mogadishu's southern district of Suqaholaha and then secondly against a police patrol in the Holwadag district.
UN-backed peace negotiations have been boycotted by insurgents and elders from the city's dominant Hawiye clan. They have yielded little progress.
Last December, the interim government, backed by Ethiopia, ousted the Union of Islamic Courts (UIC), an Islamist group that had taken control of much of southern Somalia.
Since the interim government regained control of Mogadishu in April, insurgents have mounted regular attacks against government targets.