Somalia ? A march that drew thousands in support of peacekeepers ended in violence Sunday when an explosion went off as the army chief prepared to address the rally and government troops fired into the crowd in response. At least five people were killed.

Thousands had marched through Kismayo, 260 miles southwest of the capital, Mogadishu, to support a proposed peacekeeping mission for Somalia. “Somali people need the help of Africans,” they chanted. “Somalia’s stability needs to be restored.”

It was not immediately clear what caused the explosion, which happened as Army Chief Gen. Abdi Mahdi was to address the rally at the city’s Freedom Park.

Ethiopian and Somali government troops sealed off the park after the explosion.

Col. Abdirazaq Af Gudud, a senior army official who did not take part in the rally, said three soldiers died in the explosion. The army chief was among the wounded, Gudud said.