The Chinese government has refused author Liao Yiwu an exit visa to attend the PEN World Voices Festival in New York. Authors at the event, led by Salman Rushdie, issued a protest on Friday (22 April) and called on the Chinese authority to overturn their ban. Liao is best known for his poem Massacre about the 1989 Tiananmen Square crackdown for which he spent four years in jail. The festival has vowed to set up an empty chair to represent Liao.