SHIJIAZHUANG, April 4 (Xinhua) -- The preparatory committee of the Xiongan New Area in north China's Hebei Province said Tuesday night to control illegal land and housing purchase as well as construction.

China announced on Saturday to establish the Xiongan New Area, a landmark new economic zone near Beijing designed to integrate the capital with its surrounding areas.

The announcement attracted investors to swarm into the counties of Xiongxian, Rongcheng and Anxin in the new area, and drove up housing prices there, the committee said in a statement.

The committee warned all forms of illegal trade of properties are not protected by law, and vowed to crack down on illegal construction and trading of second-hand houses.

The committee said it will strictly implement the central authorities' guideline that says "houses are for living in, not for speculating with."