CAIRO — Airport officials say Egypt has denied entry to a prominent American scholar arriving at Cairo's international airport, the latest incident in the country's sweeping crackdown on dissent.

Michele Dunne, senior associate at the Carnegie Endowment for International Peace and a former U.S. diplomat, had accepted an invitation to speak at a conference organized by the Egyptian Council for Foreign Affairs, made up primarily of former Egyptian diplomats.

In her work, Dunne is frequently critical of the Egyptian government.

Last August Human Rights Watch executive director Ken Roth and regional director Sarah Leah Whitson were also denied entry to Egypt ahead of the publication of a report accusing the government of possible crimes against humanity. Over 20,000 people have been arrested since Islamist President Mohammed Morsi's ouster last year.