A new regulation that requires women buying emergency contraceptives in at least one Chinese city to register their real names and ID card numbers has triggered an outcry on the Internet.

The food and drug watchdog in Fuzhou city, capital of the southeastern province of Fujian, announced this week that pharmacies must register their customers' details in a bid to step up control of medicine for pregnant women.

"This amounts to asking Chinese people to register before they make love," one netizen named Ding Zhengyu said on Sina's popular Twitter-like weibo on Friday.

"To make love you now need to get the agreement from relevant departments and only then can you make love, without approval you have no right to make love."

Other online posts said the rule would backfire and result in people refusing to buy contraceptives and instead risk unwanted pregnancies.

The Fuzhou watchdog said it had also issued the new requirement -- made public Monday -- to increase understanding of how contraceptives work.

An official at the watchdog surnamed Zhang told AFP that "further regulations" would be coming out "soon."

He refused to comment on why authorities have mandated buyers of emergency contraceptives to register with pharmacies.

The new rule is also expected to be implemented in Xiamen -- Fujian's second-largest city -- according to media reports.

It comes after authorities in Shanghai, Beijing and the southern province of Guangdong have starting asking microblog (weibo) users to register under their real names, as they tighten their grip on the Internet.

"You have to register your real name on weibos, you have to register your real name for contraceptives, soon you'll have to register your name to buy bicycles," one netizen said Friday.