TIANJIN - The northern port city of Tianjin announced measures Friday to restrict home owners from buying new homes to cool the property market.

Starting Saturday, single adults (including divorced individuals) and families whose members do not have permanent residence permits, or hukou, will be prohibited from buying new apartments, including second-hand ones, if they already own at least one home in Tianjin.

According to the new rule, families with local hukou who own at least two homes in the city will also be unable to buy more.

Families with local hukou who own one home, or do not own a home but have housing loan records, must pay a minimum down payment of 60 percent for a second home, while local banks will suspend housing loans with a maturity of more than 25 years.

In addition, non-resident families are allowed to buy a house only if they can provide personal income tax or social security records for at least two consecutive years in the city within the past three years.

The city's Binhai New Area is exempt from the restrictions.

Local authorities have promised to increase land supply for new apartments and to urge developers to speed up construction and sale to meet demand. Measures are set to be rolled out to restrain land prices.

About 30 Chinese cities have moved to limit housing purchases this month. In the first two months this year, investment in China's real estate market rose 8.9 percent year on year to more than 985 billion yuan ($143 billion), and housing sales jumped 26 percent from the same period of 2016 to over 1 trillion yuan.

In neighboring Beijing, 53 real estate agent offices have been permanently shut down for illegal operations, such as spreading false information on houses for sale, after a string of restrictive measures on home purchases unveiled in mid-March, the city's housing and urban-rural development commission said Friday.

The offices punished included some owned by well-known brokers, such as Lianjia and Fang.com.