A small explosion Sunday at the check-in area of Shanghai's Pudong airport injured three people, Chinese authorities said.

The blast occurred around 2:20 p.m. in a check-in area and appeared to have been caused by some sort of homemade explosive, the airport's management said on its verified microblog account.

It said the three people had been taken to a hospital but gave no word about their condition. There was no disruption to flights in or out of the busy airport, the management said.

Ni Bowen, who had been waiting to check into her Philippine Airlines flight, said passengers ran for safety after a loud bang rocked the hall.

"At that moment, a beer bottle filled with white smoke rolled right by my feet. I was scared and made off at once," said Ni, 30, who works for a machinery manufacturer.