At least nine people were killed and 40 others injured when gunmen opened fire on a gathering at St George's Greek Orthodox Church in Hmoud, in Jordan's southern Karak province, during a funeral, according to the information provided.
More than 150 people had gathered inside and outside the church to mourn the death of a community member. Health Minister Ibrahim al-Budour said two of the injured were in critical condition, saus CNN.
Security camera footage showed three gunmen opening fire in the street before advancing towards the church. Witnesses said the attackers arrived in a vehicle, got out and shot at people standing outside and in the church courtyard. At least one attacker was armed with an AK-47 assault rifle. The gunmen shouted "Allahu Akbar" during the shooting, which lasted several minutes.
Jordan's Public Security Directorate said on Friday afternoon that the attackers, whose identities had not been established, had not been captured.
Tamer Halasa, an eyewitness, told state-run Al-Mamlaka television: "Some guys were standing outside the church before two people got out of a vehicle and started shooting."
"We were more than 150 people inside and outside the church," he said.
A female survivor who escaped by hiding behind the church altar with other mourners told CNN: "It was a massacre … I did not imagine I would get out alive."
"They struck people who were gathered to grieve and mourn. I never ever imagined anything like this would ever happen anywhere in Jordan," she said.
Jordan declares three days of mourning
Jordanian leaders condemned the shooting as an act of terrorism linked to takfiri ideology, which involves declaring others to be infidels.
King Abdullah vowed a forceful response, saying: "The blood of Jordanians is precious, and we will strike those who transgress against this country with an iron fist."
The king also said Jordan would respond "harshly" to the "terrorist act".
Prime Minister Jafar Hassan declared three days of official mourning and ordered flags to be flown at half-staff over public buildings.
"What happened in Karak was the result of extremist terrorist ideology rooted in takfir (declaring others to be infidels), and we will not allow society to go down this path," Hassan said, according to the official Petra news agency.
Regional and international condemnation
Sectarian violence is rare in Jordan, where Christians account for about 2% of the population. Hmoud has been home to a Christian community for centuries.
The attack drew condemnation from governments and religious institutions across the region and beyond.
The US Embassy in Jordan said: "On behalf of the American people, we offer our most heartfelt condolences to the victims and survivors of the terror attack today at a church in Karak, Jordan."
Grand Imam Ahmed Al-Tayeb of Cairo's Al-Azhar Institute condemned the attack, saying: "This crime contradicts the teachings of the Abrahamic religions and reveals that its perpetrators are devoid of all compassion, humanity and morality."
The Latin Patriarchate of Jerusalem said: "The national cohesion of the Jordanian people serves as a vital safeguard against terrorism, extremism, and any attempts to sow division or discord."
Iraq's government also condemned the attack, saying it demonstrated that "terrorism is a root of evil that the Iraqi people have previously suffered from and confronted with determination and strength".
The Iraqi government called for unity against forces that threaten the security of societies and undermine civil peace.