In a surprise move Tuesday, the Thai army assumed responsibility for national security “to preserve law and order” but denied it was a coup.. An army spokesman said that the imposition of martial law, after a long-running political crisis, will have no impact on the caretaker government which remains in office. But the government had not been consulted in advance. The move came on day after the caretaker prime minister refused to step down. The military prohibited “all media outlets from the reporting or distribution of any news or still photographs detrimental to national security.”