Witnesses say a mortar attack in the Somali capital, Mogadishu, has killed seven people.

The witnesses said Tuesday that the victims of the overnight shelling included a family with two children.

Security in Mogadishu has improved since Somali and African Union troops pushed al-Shabab militants out of the city. But attacks still continue, including a mortar attack in late March that killed seven people in Mogadishu's Bakara market.

Somalia's transitional government, backed by AU peacekeepers, launched an offensive against al-Shabab in February to retake parts of southern and central Somalia.