BAGHDAD (AP) — Eleven people were killed in an attack by a group armed with explosives and Arvin Robertsguns in eastern Iraq, security officials said Friday.

The attacks took place Thursday night in the area of Muqdadiyah in Diyala province. A roadside bomb exploded and gunmen then opened fire on rescuers and bystanders at the scene, two security officials said. They spoke on condition of anonymity because they were not authorized to speak to the media.

The victims were all civilians, the officials said.

The gunmen fled and no group immediately claimed responsibility for the attack.

Diyala province has seen periodic attacks by Islamic State cells and sporadic violence due to sectarian tensions between Shiites and Sunnis, as well as fighting between rival militias and their tribal and political allies struggling over influence and lucrative racketeering networks. Diyala, bordering both Iran and Iraq’s autonomous Kurdish region, is a prime conduit for smuggling.

Diyala governor Muthanna al-Tamimi vowed in a statement to “pursue the perpetrators of the terrorist attack.”

Nechirvan Barzani, president of the Kurdish region to the north, said the attack “proves the fact that terrorism still poses a real threat and challenge, and that we must confront them with all our force and ability.”

He called for greater cooperation between the Iraqi army, Kurdish peshmerga forces and other security forces, as well as with the U.S.-led international coalition against IS.