BEIJING - China will continue to maintain a firm grip of its real estate market and consolidate previous achievements in bringing down home prices so as to prevent them from rebounding, according to an urgent government notice released Thursday.

"Local authorities must strictly implement the nation's property control policies. They should not relax the control and relevant requirements unauthorized," according to the notice.

"Those that have loosened up controls must set straight the policies," said the notice, which was jointly released by the Ministry of Land Resources and the Ministry of Housing and Urban-Rural Development.

It also ordered local authorities to step up efforts in monitoring land pieces left idle even though they were sold.

The latest announcement came as the nation's housing prices and sales both showed signs of warming. Official data released Wednesday showed that 25 cities, out of a statistical pool of 70 major cities, saw new home prices rise in June from the previous month. The figure was drastically up from six cities that saw month-on-month price gains in May.

"Fluctuations have appeared recently in the property market and land market. Although they have not changed the overall picture, the complexities and instabilities have increased in the market," said the notice.

The notice ordered that local authorities prioritize land supplies for affordable housing. Meanwhile, supplies for ordinary commercial residential houses should be further increased, according to the notice.

The notice also said that the Ministry of Land Resources will enhance monitoring of the nation's land market in order to prevent the occurrence of high-priced land pieces for both commercial and residential property.

Local governments should set a reasonable starting price for land-use- right transfers. Meanwhile, local governments should make adjustments in advance to land auction plans if the land pieces involved are highly likely to see record bidding prices, the notice said.

Ma Xiaoming, a senior NBS statistician, attributed the recent price warming to recent interest rate cuts implemented by the government to bolster the slowing economy and the altering mind-set of home buyers who fear the prices will further pick up.

China has tightened its curbs on the property sector since 2010 as home prices rocketed beyond the reach of average wage earners. The government has restricted home purchases in several cities while requiring higher down payments and introducing property taxes. The clamp-down has since cooled the market gradually.

The central authorities have reiterated their firm stance on property market regulation many times this year.

Premier Wen Jiabao said earlier this month the government must make unswerving efforts to ensure house prices return to reasonable levels and block a price rebound that would undermine the effects of previous efforts.