Police estimate that about 300 people took part in the demonstration for peace, which had been organised by the Somali League in Finland.
Before the march, the demonstrators discussed the situation in Somalia. Ethiopian forces had entered the country at the request of the provisional government of Somalia. The United States had conducted air strikes in the south of the country, where it says local al-Qaeda leaders are staying.
Abdullah Ayah feels that it is inconceivable that foreign forces will roll into a country on the pretext of driving Islamist forces out. He says that two of his uncles have been killed in the violence.
"The Islamists were in power for six months. In Mogadishu and nearby areas they achieved peace."
Ayah feels that as citizens of Somalia, the Islamists have the same rights as anyone else.
"This makes us very angry. Although the United States and the UN try to stop the Islamists, this way they are creating more of them."
The demonstrators did not have much understanding for the provisional government in Somalia, which is seen as a puppet of Ethiopia and the United States. However, the mistakes of the deposed Islamists were also acknowledged.
"For instance, banning smoking was a premature decision", Murshed Sayid said.
Muhammud Yusuf was annoyed by talk of the Islamists.
"They are citizens of Somalia and they do not model themselves after al-Qaeda."
Many visit Somalia on a regular basis. Now this is not possible, because the country is in a chaotic state.
"I would like to go to my own country and show it to my children", Mahmed Shire said.
The march, which began soon after two in the afternoon, proceeded up Mannerheimintie to the Esplanade, where a small delegation delivered the views of the demonstrators to representatives of the European Union.
The marchers shouted slogans accusing President Bush of being a murderer and a terrorist.
The demonstrators also demanded that Ethiopia withdraw its forces from Somalia, and that the United States stop its air strikes and stop helping Ethiopian forces.
From the Esplanade, the march continued to Kaivopuisto park, where they were faced with police columns and riot fences. Five representatives of the demonstrators were allowed through the barricades to deliver their statement to the United States Embassy.
"We said that we do not hate the Americans, but that we are enemies, because they are bombing Somalia. I was speaking on behalf of the women and children", said Saido Mohamed.
Finally, the protesters prayed in Kaivopuisto.