Jordanian security forces have arrested three suspects over the deadly attack on a church in the Karak governorate, the state-run Petra news agency reported on Monday.
The attack, in which gunmen opened fire on the church in the village of Hamoud in Karak, killed nine people and injured 40. Jordan's Public Security Directorate said the three suspects were found hiding in an abandoned house early on Monday.
The suspects refused to surrender and opened fire on the security forces, who returned fire and arrested all three after they were wounded. No security personnel were injured and firearms and ammunition were seized, the directorate added.
Its statement did not identify the suspects' affiliation or say whether they belonged to any militant group.
Jordanian Interior Minister Mazen Al Farrayeh said the government was determined to reassure the public by taking action after the killings. Authorities will hold anyone involved to account, it added.
Mr Al Farrayeh said on Friday that the attack was carried out by extremists, but that it was too early to determine whether they had links to known groups inside or outside Jordan. No group has claimed responsibility.
Hundreds of Jordanians from across the kingdom attended a funeral service for eight of the nine Christians killed in the attack. The service was held at the church where the attack took place.
On Friday, King Abdullah II had said the attack would be met with force. He vowed to crack down on those responsible and said the shooting would not undermine national unity. He also described the attack as "terrorism".