Facebook has apologized after a Palestinian man was arrested by Israeli police for a post saying “good morning” that its automatic-translation service erroneously translated as “attack them” in Hebrew and “hurt them” in English, reports Israeli newspaper Haaretz. The man is a construction worker near Jerusalem, reports The Guardian. He posted a photo of himself last week leaning against a bulldozer with the caption “يصبحهم”, or “yusbihuhum,” which translates as “good morning.”

Police arrested the man after they were notified of the post and were suspicious he was planning a vehicle attack using the bulldozer. He was released hours later after police realized the mistake. Haaretz reports that before his arrest, no Arabic-speaking officer had read the man’s Facebook post.

Facebook is currently investigating the issue and Necip Fazil Ayan, an engineering manager in Facebook’s language technologies group, said in a statement to Gizmodo that though mistakes might happen, the company’s translations are getting better each day. “Unfortunately, our translation systems made an error last week that misinterpreted what this individual posted. We apologize to him and his family for the mistake and the disruption this caused.”

Facebook’s translations are entirely powered by AI, and around 4.5 billion translations are made each day across the social network.