The government of Shenzhen, China’s southern technology hub, auctioned off five residential land parcels Monday for a total of more than 22.4 billion yuan ($3.2 billion), setting a single-day sales record.

The auction attracted 71 developers, which put up a record 98.7 billion yuan in deposits to participate. The response was another signal that the Shenzhen housing market is heating up after a two-year slowdown as regulators slammed on the brakes. Official data showed that new home sales rose 79.6% year-on-year in May, with average prices up 1.24%.

Residential land has been scarce in the city of 12.53 million, where the booming tech sector continues attracting migrants. Between 2015 and 2018, the city government added only 18 plots to the market for residential development, according to data from Midland Realty. The Monday sale was the first auction of land for residential development so far this year.

The parcels, with a combined area of 170,273 square meters (1.8 million square feet), sold at prices 45% higher than the minimum bids. Guangdong government-backed Yuexiu Property Co., Logan Property Holdings, China Overseas Land, PowerChina Real Estate Group and a unit of Ping An Insurance Group’s venture capital arm were the winning bidders.

Related: Jump in One Lower-Tier City's Land Prices Hints at Sharp Real Estate Recovery