The German city of Trier was in mourning on Wednesday, a day after a car drove through a pedestrian area, killing five people, and injuring 14.

Mayor Wolfram Leibe called Tuesday's fatal incident the "blackest day in the city of Trier after the Second World War."

Hundreds of people gathered at Porta Nigra, Trier's iconic Roman landmark, on Wednesday morning. It was the first official ceremony in memory of the five people killed on Tuesday, when a large SUV plowed through the Western German city's pedestrian area, in what onlookers described as a deliberate attack. 

"It is a sad day," Malu Dreyer, state premier of Rhineland-Palatinate said in the ceremony that was broadcasted live via the internet. "My voice is failing me, thinking about the mother who has lost her child and her husband. Never again will she hear their laughter, their voices. She will be burdened by the consequences of these four deadly minutes for the rest of her life."

Dreyer, Leibe, and dozens of mourners laid wreaths and flowers in front of the 1800-year-old grey sandstones of the Porta Nigra. The attacker had driven past the landmark as he seemed to be deliberately chasing pedestrians. Witnesses said his large SUV traveled at high speed on Tuesday afternoon, tossing some people into the air. A nine-week-old baby girl and her father were killed, as well as three women, aged 25, 52 and 73. Several of the injured are still fighting for their lives.

Leibe, a red rose in his hands, told the mask-wearing crowd: "Today, our sympathy goes out to the people who are affected, to the families. The dead, the seriously injured, the injured, and the many traumatized who had to experience people dying next to them."

Leibe was fighting tears as he said that Trier was a small city where people knew each other. When he visited the scene on Tuesday, he said, he recognized some of the victims, too.

"Please comfort each other," Leibe said. He thanked the first responders who had rushed to the scene. "They have experienced more than can be expected of people", Leibe added to a round of applause from the crowd.

Charges may include murder

Police are still questioning the 51-year-old male driver of the SUV.

Rhineland-Palatinate Interior Minister Roger Lewentz said he believed the driver had intentionally targeted pedestrians, driving in "zigzag lines" to do the most damage.

Prosecutors are working on the assumption that there was not a political or religious motivation behind the incident. But officials are considering multiple charges of murder, attempted murder, and dangerous bodily harm.

According to the public prosecutor's office's initial findings, the suspect may have a mental illness, the DPA news agency reported. That would leave judicial authorities to decide whether to request the suspect be remanded in custody or placed in a closed psychiatric institution.

Police said the man had been living out of his vehicle during the past few days. Public prosecutors Peter Fritzen said the man was drunk at the time of the crime and had resisted arrest.

'Inhumane attacks must have no place in our society'

Late on Tuesday, as many as 150 people had already attended a prayer service for the victims at the city's cathedral.

On the stairs leading to the altar room, visitors placed candles and cuddly toys to remember those who were killed.

One of Germany's most senior clerics also passed on his condolences.

"In this hour of speechlessness and sadness, I am united with the victims, the deceased, the injured and their relatives," said Georg Bätzing, the chairman of the Catholic Bishops' Conference.

Bätzing, who is also the bishop of Limburg, said: "Inhumane attacks must have no place in our society."

jf/sms (AFP, dpa)