Fifteen people were injured and three small sharks died in an explosion at an aquarium in a bustling shopping area of Shanghai.

The blast on Tuesday occurred in the city's East Nanjing Pedestrian Road.

No official reason for the explosion has been given by the Shanghai Oriental Shopping Center, the aquarium owner. But some people believe it was a result of contraction caused by cold weather, with temperatures in Shanghai dropping suddenly on Tuesday.

All of the injured, except for one victim with a broken ankle, were released from hospital on the night of the accident. Most of the injured are staff from the shopping center.

The center resumed business on Wednesday, but some cosmetics counters near the aquarium were badly damaged, said a salesman.

A vendor selling shoes outside the shopping center said, "It was horrible, like a bomb explosion. Some pedestrians were pushed two meters away by the force of the water."

It is the second explosion this year at the aquarium. In June, a blast there killed two small sharks.