Bishop Gerhard Feige of Magdeburg said that the "brutal attack" left the community "sad and angry, helpless and fearful, uncertain and desperate, speechless and stunned, and deeply affected."

He continued: "We are here in the cathedral tonight with feelings that cannot be grasped."

The service was attended by injured victims, relatives and rescue workers as well as the country's President Frank-Walter Steinmeier and Chancellor Olaf Scholz. Hundreds of people also followed the service on the cathedral square in the cold and rain via a screen broadcast.

Pope Francis sent a telegram to the German president, expressing he "learned with dismay" about the attack.

"His Holiness expresses his participation in the grief of those affected," the telegram, sent by Secretary of State Cardinal Pietro Parolin said. It added the Holy Father "assures all the victims his spiritual closeness." The pope thanked those "supporting the victims during this difficult time," invoking "divine consolation" to all those who lost their lives.

Church bells rang at 7:04 p.m. in Magdeburg, the exact time of the attack in the city 80 miles west of Berlin, where roughly 240,000 people live.

The attacker who ploughed a car into a crowd of shoppers is a 50-year-old doctor who immigrated from Saudi Arabia in 2006, and who surrendered to police at the scene.

"Together, we are here tonight to give each other support, to endure what is incomprehensible. We are here together because we will not let hatred and violence have the last word," Bishop Faige said during the prayer service. "Together we stand by the side of those who are mourning the loss of someone, who are afraid for injured relatives or who were at the Christmas market on Friday and are still in shock and need to come to terms with what they have seen and what has happened."

Protestant Bishop Friedrich Kramer said in his sermon: "We are shocked and ask ourselves: Is there still a safe place, a place of peace?" Perpetrators of violence sit on "the throne of attention." Bishop Kramer continued: "Let us not give this perpetrator of violence any space."

Initial speculation about a possible Islamist background to the attack is now considered unlikely.

Just three minutes away from the scene of the horror attack, the local community organized a memorial, laying flowers and cuddly toys in front of St. John's Church in Magdeburg's city center.

Emergency counsellor Corinna Pagels was on the scene on the evening of the crime. She was standing in front of St. John's, looking after the mourners who came to the memorial site. "Listening, hugging, comforting" is what she did throughout the evening of Dec. 20, she said.

All available emergency counselors and crisis intervention teams from all over the region of Saxony-Anhalt were on duty in Magdeburg that evening. "We are now in the hospitals, on the children's wards and here at the scene of the incident -- for many people, the shock is only now really sinking in. Many are traumatized," Pagels told KNA German Catholic news agency.

Pagels also has an image of the night of the crime that she can no longer shake off: "There was a dead woman lying there. And her grieving husband was lying on top of her and just didn't want to get up and let go of his wife." Her colleague told her of an injured child lying next to his injured mother, screaming loudly in pain and fear.

Such a horrific attack happening just four days before Christmas Eve left Pagels deeply shaken. "I don't think we'll be putting up a tree this year. Christmas has taken on a different meaning now," she told KNA.

Chancellor Scholtz promised the state's support for all those who have fallen victim to this "terrible, insane act."

Earlier on Dec. 21, Bishop Georg Bätzing, president of the German bishops' conference, and Bishop Kirsten Fehrs, chair of the Council of the Evangelical Church in Germany, said: "Our thoughts and prayers are in Magdeburg at this time."

"The inhumane attack in Magdeburg leaves us stunned," they added. "The horror, grief and sympathy are felt by many people throughout Germany and the world today."

So many innocent people "fell victim to this senseless violence just before Christmas," Bishop Bätzing and Bishop Fehrs continued. "Our thanks go to the dedicated emergency services, who have been caring for the injured since yesterday and are working hard to find out what happened, as well as to the emergency counsellors who are supporting people at this moment and accompanying traumatized people."