KUALA LUMPUR, Malaysia — Authorities here said they will likely repatriate a Saudi Arabian writer who fled Saudi Arabia amid calls for him to be executed after he posted Twitter messages considered insulting to the Prophet Muhammad, Malaysian authorities said Friday.

Malaysian police detained the writer, Hamza Kashgari, a 23-year-old columnist for the Jeddah-based Al Bilad newspaper, when he arrived at Kuala Lumpur International Airport on Thursday, Hishammuddin Hussein, the Malaysian Minister of Home Affairs, said in a statement.

“The police have contacted their counterpart in Saudi Arabia to determine the next course of action,” Mr. Hussein said.

Rights groups have expressed concern about Mr. Kashgari’s safety after religious conservatives in Saudi Arabia called for him to be arrested and executed after he directly addressed the Prophet Muhammad in a series of posts on Twitter. Amnesty International called for Malaysia not to deport Mr. Kashgari, to immediately disclose where he is being held and to grant him access to a lawyer.