We've been waiting for tightening measures to hit the Beijing property market, especially after the city's real estate association itself said the situation was a bubble.

It looks like the government's clampdown is starting to bite, hard. Average Beijing transaction prices collapsed 31% month on month:

Capital Vue:

The average transaction price of commercial residential properties in Beijing for the week ended May 9 fell 1,790 yuan per square meter or 9.6 percent week-on-week to 16,898 yuan per square meter, reports The Beijing News, citing statistics released by Beijing Real Estate Information Network.

Compared with the week ended April 11, the average transaction price of commercial residential properties in Beijing plunged 31.43 percent to 7,744 yuan per square meter.

In the last weeks of April, the transaction volume of commercial residential properties in Beijing decreased by 10.34 percent, 11.39 percent and 30.82 percent respectively. Average transaction price was flat at between 22,000 yuan to 23,000 yuan per square meter.

Next up? Shanghai.

They're introducing further restrictions on property later this month, such as hiking taxes on owners of multiple properties, according to Shanghai Security News.

Now see: Why Shanghai real estate is the most obvious bubble ever >