KINSHASA, Democratic Republic of Congo — The Islamic State has claimed its first attack in the Democratic Republic of Congo, planting a flag in a region already troubled by violence and an outbreak of the Ebola virus.

Eight soldiers were killed in the attack, which took place on Tuesday, according to Congolese officials. They initially said that the assailants appeared to have belonged to the Allied Democratic Forces, a rebel group with origins in neighboring Uganda that is accused of killing hundreds of people over the past three years.

But on Thursday Islamic State propagandists asserted responsibility and described Congo as the “Central Africa Province of the Caliphate,” according to the SITE Intelligence Group, which monitors Islamic State announcements.

It was the first time that the Islamic State has asserted responsibility for an attack in Congo, a vast country where the central government has limited reach and where rebel groups have proliferated for many years.