About 100 demonstrators had gathered Monday morning to protest electricity and water outages in the capital of Conakry.
Mohamed Bangoura, who took part in the protest, said several of the participants were wounded when police intervened.
Demonstrators said the outages were particularly difficult as they are coming during the holy Muslim month of Ramadan, when people are fasting until sundown each day.
Guinea's finances were left in ruins after nearly a quarter-century of rule by Lansana Conte, who pillaged state coffers to make his family fabulously wealthy before his death in 2008.
In 2010, the country held its first democratic election ever though most Guineans remain deeply impoverished nearly two years later.
Copyright © 2012 The Associated Press.