The government called the shooting a terrorist act. As of Saturday no group had claimed responsibility, and the motive was unknown. A government statement said the attack was "carried out by unknown assailants" and that investigations were underway. It did not say whether any suspects had been caught. A manhunt for the attackers is underway.

Reports name the village where the church stands in three ways: Hammoud, Hamoud or Karak. They also disagree on how far south of Amman it is.

Accounts of the attackers differ, though all describe three men. Footage aired by Jordanian state television, as several reports described it, showed two men with pistols and a third with a rifle or other long gun. One of those reports said the men wore ordinary clothes. Another account said three masked men carrying automatic weapons fired indiscriminately at mourners outside the church. Some reports said the gunmen arrived in a vehicle and fired at people gathered near the church, while others said they went inside.

Mourner Dorgham Halasa said the gunfire began 15 minutes into the service. One eyewitness estimated the gunmen fired for about five minutes into a crowd of 150 to 200 people, most of them between 50 and 70 years old. Survivor Saed al-Halaseh said the gunmen came back to fire more shots at the dying and at the front of the church. Video from witnesses showed shattered glass and blood on the floor.

King Abdullah II promised "the harshest retaliation" and said he would "strike with an iron fist." He went to Karak on Friday evening. Officials announced three days of national mourning. Jordan's interior minister said security agencies were investigating and described the attackers as a "group of extremists."

United Nations Secretary-General Antonio Guterres, Al-Azhar Grand Imam Ahmed al-Tayeb and Lebanese President Joseph Aoun each condemned the shooting as a "heinous terrorist attack." Aoun said it aimed to damage peaceful coexistence.

Christians make up about two to three percent of Jordan's population. Karak has a sizeable Christian community and has long been seen as a symbol of religious coexistence. Al-Halaseh said the shooting had shattered that. In 2016, an ambush by gunmen in Karak killed 10 people, seven of them police officers.