A knife-wielding bank robbery suspect has drawn laughter from a bank clerk and netizens for his farcical attempt, cctv.com reported on Monday.

Surveillance video of the failed robbery shows the man holding a cellphone walking around at a branch of the China Construction Bank in Hongkou district in Shanghai on Feb 20.

At about 12:40 pm, he followed a female client to the No 2 counter. He pulled a kitchen knife from his coat as he chatted on the phone, and then threatened to rob the bank.

The female client immediately walked off. The teller was safely behind a glass partition and did not appear frightened, but instead appeared to point the knife out to a colleague with a laugh.

The bank’s security guards evacuated all customers and controlled the man, who did not offer much resistance.

The man is reported to be suffering mental illness and police are investigating the case.