The Johanniskirche, a church a short walk from the scene of the attack, has become a central place of mourning since the suspect drove a car into the busy market on Friday evening, killing five people. A carpet of flowers now covers the broad pavement in front of the church.
Prosecutors said the number of injured had risen to up to 235 as more people had reported to hospitals and doctors, but that it was possible there was some double-counting.
Authorities have identified the suspect as a Saudi doctor who arrived in Germany in 2006 and had received permanent residency status. They say he does not fit the usual profile of perpetrators of extremist attacks.
The man described himself as an ex-Muslim who was highly critical of Islam and in many posts on social media expressed support for the far-right.
A picture has emerged of someone who had come to authorities’ attention in the past for threatening behaviour and been the subject of tip-offs, but was not known to have committed any violence.
German Interior Minister Nancy Faeser said on Sunday that “the views and statements that the perpetrator expressed are being investigated, as are the tipoffs and proceedings with various authorities and the justice system”.
She said “the right conclusions” will then have to be drawn.
The country’s vice chancellor Robert Habeck voiced fears that the attack will fuel online misinformation ahead of a national election expected in late February.
He urged people to “take time for the truth” and said: “Don’t let yourselves be infected by hatred.”
“There is still a lot we don’t know and a lot is unexplained, including the exact motive,” Mr Habeck said in a video posted on Sunday.
“All the same, I fear that the distrust that was immediately propagated on the net against Muslims, foreigners and people with a history of immigration will entrench itself deeper in society”.
On Sunday night, police in the port city of Bremerhaven said they detained a man who threatened crimes at a Christmas market there in a TikTok video.
German news agency dpa reported that he had said he would stab any people of Arabic appearance there on Christmas Day.