Surprised Singaporeans pursued North Korean leader Kim Jong Un on Sunday before realizing the portly man with slick black hair near the Marina Bay Sands hotel was an impersonator.

"It looked like the real Kim Jong Un, but later I realized it's not the real one," said Sagar Admuthe, who was visiting from Mumbai, after several selfies with the doppelganger against a backdrop of the city's bay.

"When you see him, it's very difficult to make out."