Mortar shells fired by suspected Islamist insurgents have killed a mother and her three children in Somalia's capital.

Witnesses say one of the shells landed on the family's home late Sunday. They say the children's father and grandmother were wounded.

Residents say shells hit two other homes in the area, causing more injuries.

Earlier Sunday, Ethiopian troops based in a Mogadishu football stadium exchanged mortar fire with unidentified attackers. The Associated Press reports four people were wounded in the exchange.

Insurgents have been battling the Somali government and allied Ethiopian troops since January, shortly after the government ousted a rival Islamist movement from power in Mogadishu.

The almost daily battles have caused thousands of deaths and prompted more than 100,000 people to flee the city.

Islamist leaders and other opponents of the government have been meeting in Eritrea's capital, Asmara, for the past week. Speakers have repeatedly condemned Ethiopia's military support for the Somali government.

The interim government, with the backing of Ethiopia and the U.N., has struggled to assert authority throughout Somalia.

Somalia has not had a stable central government since warlords pushed dictator Mohamed Siad Barre from power in 1991.