At 8.30pm, police were notified that three people, including security guards and a delivery man, were injured after an assault at The Mall Ngam Wong Wan branch.
The injured were sent to Nonthavej Hospital.
The assailant, 33, reportedly came to the mall without wearing a face mask and a security guard asked him to leave. He then had an argument with the guard before going berserk and stabbing people nearby.
He was identified as a former convict who had served jail terms three times in Chiang Mai prison for robbery. The police also found an HIV patient card on him.
He was taken to Muang Nonthaburi Police Station for interrogation and initially charged with attempt to murder.