Iraq’s Christian community is in shock after the murder on Sunday of three people including a newly engaged man and a woman just a year into her marriage.

Susan Latif David and her mother-in-law, Muna Banna David, were killed after armed men knocked and entered their home at around 7pm in the Domeez section of Iraq’s eastern city of Kirkuk.

At about the same time in another part of the city, Basil Shaba was murdered in a similar attack. His brother, Thamir, and father, Yousif, were injured in the same attack.

After conducting the funeral in a packed Kirkuk Cathedral, Archbishop Louis Sako told Aid to the Church in Need of “the tears and sadness” of a people mourning the deaths of three “innocent loved ones”.

Susan Latif David, he explained, had been married for only one year. Her husband owns a restaurant near the cathedral.

Both Susan Latif David and her mother-in-law were Chaldean Catholic but Mr Shaba who, Archbishop Sako said had only recently got engaged, was Syrian Orthodox.

In his interview with the Catholic charity for persecuted and other suffering Christians, an emotional Archbishop Sako described the funeral.

He said: “People were crying. We are all so sad. We only hope that the blood of the martyrs will one day bring us peace and stability.”

Nobody has yet been arrested in connection with the deaths but Archbishop Sako said that it was already clear that the murders were premeditated and that one probable key motive was to “force Christians to leave”.

He added: “We will not leave Iraq. We have a mission to stay here. We have to give witness to our Christian values. Even if they try to kill us we will stay.”

Aid to the Church in Need UK director Neville Kyrke-Smith said the charity “offered solidarity in faith” and prayerful support to the grief-stricken.

He said: “ACN calls on all to stand by their brothers and sisters in charity. The Christians of Iraq continue to suffer a long Good Friday every day and as yet know little of the hope of the Resurrection.”

Archbishop Sako said that Kirkuk’s police chief had personally told him he “will do everything to ensure that those responsible will be arrested”.

The Archbishop said that leaders from across Kirkuk had come for the funeral, including the mayor and leading sheikhs, and that there had been widespread condemnation of the attacks.

Describing the probable motives for the killings as “complicated”, Archbishop Sako said that the attacks could be linked to the ongoing uncertainty over Kirkuk’s political future either as part of the semi-autonomous Kurdish region in the north or under the jurisdiction of Baghdad.

The killings come less than a month after a spate of murders of Christians across Iraq, including Kirkuk.

Sabah Aziz Solaiman, 71, was killed during a robbery in Kirkuk on the morning of 31 March.

Next day Nimroud Khodir Moshi was murdered outside his Baghdad restaurant and elsewhere in the capital, two sisters were killed. Electrical generator operator repairman Abdul Aziz Elias Aziz was killed in Mosul.

The murders prompted Archbishop Sako to warn of a security “vacuum” opening up as a result of US military withdrawal from Iraq, which he said could lead to “civil war” and “Iraq’s division”.