More than 180 writers, including Nobel laureates Olga Tokarczuk and JM Coetzee, have signed an open letter demanding proof of life for 12 Eritrean authors who have been held incommunicado since a government crackdown in September 2001. The letter, organised by PEN International (the global writers' rights organisation) and addressed to Eritrean president Isaias Afwerki, marks 25 years since the authorities crushed the country's independent press and detained the writers — among them poet Amanuel Asrat and journalist Dawit Isaak — without any communication to their families or the public since. Eritrea, which has held no national elections since independence in 1993, is widely regarded as one of the world's most repressive states, and PEN International's president Burhan Sönmez said the organisation would "continue to demand the truth" until the detained writers are freed.