BEIJING (AFP) - A Chinese teenager has been detained for allegedly obtaining thousands of dollars in donations after falsely claiming her father was killed in devastating explosions in Tianjin, the police said on Sunday.

The teenager surnamed Yang had initially claimed on microblogging platform Sina Weibo that her father was missing as a result of the blasts, which triggered a massive fireball in the northern port city, leaving 112 people dead and hundreds more hospitalised.

The 19-year-old - who was detained by police in Fangchenggang in the southern region of Guangxi, far from Tianjin - saw her Weibo follower numbers shoot up as a result of the post, the Fangchenggang police said on their verified Weibo account.

According to the police, she then published a second post in which she claimed her father died in the explosions, spurring more than 3,000 fellow users to donate upwards of 90,000 yuan (S$20,000) via the social media platform.

Weibo has recently added a reward function, allowing users to transfer funds to others via its own platform, ostensibly to show appreciation.

Ms Yang was unable to withdraw the funds, however, as her account was frozen after several Weibo users reported her as suspicious, the police said.

Though she was detained for allegedly defrauding users, a vast online censorship system operates in China and the authorities have launched a wider crackdown against criticism of the disaster's handling and aftermath.

A total of 50 websites have been shut down or suspended for "creating panic by publishing unverified information or letting users spread groundless rumours", according to the Cyberspace Administration of China.

Critical posts on social media have also been blocked, with action taken against more than 360 social media accounts.

A man surnamed Kang would also be held under "administrative detention" for five days for "spreading rumours", Tianjin police said on their verified Weibo account.

Under Chinese law, the punishment is applied to those declared by police to be guilty of minor offences. There is no trial.