A driver in Leipzig, Germany, drove into pedestrians in a central shopping area on Monday, killing two people and seriously injuring two others.

About 20 additional people were also affected, according to local fire officials.

Police detained the suspect at the scene after he stopped the vehicle himself.

Authorities identified him as a 33-year-old German citizen and said the incident is believed to be isolated, CBS News has reported.

No motive has been determined, and officials said investigations are ongoing.