Authorities in Congo urged churches, restaurants and hotels to step up security, fearing more violence after a suicide bomber killed five people in eastern Congo in the first attack of its kind.

Beni mayor Narcisse Muteba, a police colonel, warned owners of popular venues in the town that they needed to add security guards with metal detectors because “terrorists” could strike again.

“We are asking people to be vigilant and to avoid public places during this festive period,” the police colonel told The Associated Press on Sunday.

Officials initially said the death toll was six plus the suicide bomber, but Mr Muteba revised that figure a day later to five victims.

Thirteen others remained in hospital after the blast at the entrance to the Inbox restaurant on Christmas Day.

Saturday’s bloodshed dramatically deepened fears that Islamic extremism has taken hold in Beni, which has already suffered years of attacks by rebels from the Allied Democratic Forces, or ADF.

Mr Muteba blamed the latest attack on those rebels, whose exact links to international extremist groups have been murky. The so-called Islamic State (IS) group’s Central Africa Province has claimed responsibility for attacks blamed on ADF, but it is unknown what role the larger organisation may have played in organising and financing these.

There have been worrying signs that religious extremism is escalating around Beni, with two local imams killed earlier this year within weeks of each other, one of whom had spoken out against the ADF.

Then, in June, the IS group’s Central Africa Province claimed responsibility for a suicide bomber who blew himself up near a bar in Beni without harming others. Another explosion that same day at a Catholic church wounded two people.

There was no immediate claim of responsibility for Saturday’s attack, in which authorities say the bomber was ultimately stopped from entering the crowded restaurant.

After the blast near the entrance, blood stains could be seen on the pavement and mangled chairs lay strewn nearby.