An opposition group in Djibouti claims that 19 were killed after a clash between police and revellers celebrating a religious festival turned violent.
Government officials dispute this figure and say that nine were wounded.
Independent reports to verify the real figure were not yet available.
The country has often been the scene of sporadic violence , usually sparked by protests against the government of President Ismail Omar Guelleh.
Kadar Abdi Ibraim, a spokesman for the opposition coalition Union pour le Salut National said police had started the violence by attacking people at the festival, which had been banned.
An interior ministry spokesman said “dozens of armed individuals” launched an attack in the Buldhoqo area in an attempt to “destabilise our nation and sow divisions”.
He said nine people were wounded, including a police officer.
In 2011, anti-government demonstrators, who were buoyed by the revolutions then sweeping North Africa, demanded Guelleh step down.
The authorities cracked down hard on the opposition.
The president has been in power since 1999 and a new presidential election is scheduled for April 2016.