China said Thursday it had cracked three spying plots, including one in which a public servant was lured by the "seductive beauty" of a foreign agent, urging government workers to remain vigilant against overseas threats.

Beijing has stepped up espionage warnings in recent years as relations with the United States and other Western nations have worsened.

Its state security ministry said Thursday that foreign spooks "have been increasingly active in infiltrating and stealing secrets from China" and were targeting public officials.