Lon Nol resigned as prime minister in early May 1967, and Sihanouk appointed Son Sann in his place. At the same time, Sihanouk replaced conservative-leaning ministers appointed by Lon Nol with technocrats and left-leaning politicians. In the later part of the month, after receiving news that the Chinese embassy in Cambodia had published and distributed Communist propaganda to the Cambodian populace praising the Cultural Revolution, Sihanouk accused China of supporting local Chinese Cambodians in engaging in "contraband" and "subversive" activities. In August 1967, Sihanouk sent to China his Foreign Minister, Norodom Phurissara, who unsuccessfully urged Zhou to stop the Chinese embassy from disseminating Communist propaganda. In response, Sihanouk closed the CambodiaChinese Friendship Association in September 1967. When the Chinese government protested, Sihanouk threatened to close the Chinese embassy in Cambodia. Zhou stepped in to placate Sihanouk, and compromised by instructing its embassy to send its publications to Cambodia's information ministry for vetting prior to distribution.