This poster was issued by the Beijing United Medical Students Association in Support of the Shanghai Incident (Beijing Xiehe Yixue Xuesheng Hu'an Houyuanhui - 北京协和医学学生沪案后援会).

Below the image is a text in French, German, English, Chinese and Japanese. The English text in the middle reads:
"The Chinese Magistrate asked whether firing at the legs of the crowd would have been effective. Inspector Everson said that such would be contrary to his instructions, which were only to fire in the last resource and then to shoot to kill."
Reuter
Shanghai 10 June, 1925