At least three people were injured after explosives went off in Shanghai Pudong International Airport on Sunday afternoon, according to state media reports.
The explosives were "self-made with firecrackers" and further investigation was under way, the official Xinhua news agency said on its Twitter account.
Flights have been undisturbed, Xinhua added.
Xinhua also posted photos from travellers' social media accounts showing crowds gathered near check-in desks and medical staff taking one victim away on a gurney.
The incident took place around 2:30 pm (0630 GMT) inside Terminal 2 of the airport, according to the official Weibo microblog account of the state-owned Xinmin Evening News based in Shanghai.
"Many online commentators told Xinmin News that at the time they saw smoke coming from the ticket counters. After that, police officers and armed policemen arrived and part of the airport was quarantined," Xinmin Evening News said in its Weibo post.
Travellers' photos collected by the Xian Evening News' official Weibo account showed police officers cordoning off sections of the airport near ticket counters.
No news reports or travellers' online accounts identified any perpetrators.