State radio reported on Thursday that the worst incidents occurred in the districts of Koumassi and Abobo, prompting United Nations Secretary-General Kofi Annan to appeal for an immediate end to the clashes.
The violent flare-up threatened the West African nation's peace process as opposition parties and former rebels quit the unity regime in protest against the 'repressive measures' of the security forces in quelling demonstrations against President Laurent Gbagbo.
The Union for Democracy and Peace in Ivory Coast, a political party founded by a slain former military ruler, pulled two of its ministers out of the government.
The country's main opposition party, the Rally of Republicans, also said it was withdrawing from the unity government set up under the January 2003 peace pact.
UN Secretary-General Kofi Annan, meanwhile, urged all parties to bury their differences and put national interest foremost.
"At a time when the UN is preparing the deployment of a peacekeeping operation, the Ivorian parties must demonstrate the political will to reject all forms of violence and engage in genuine reconciliation and mutual accommodation," he added.
Rebels in Ivory Coast, the world's top producer of cocoa, rose up in September 2002 to oust Gbagbo. The rebellion quickly boiled over into civil war.
The country remains divided, with rebels holding the north, despite a peace accord signed 14 months ago.
The UN Security Council voted last month to create a new 6,000-strong UN peacekeeping force for the country, in addition to the 4,000 French troops already on the ground.