Human Rights Watch (HRW) said on Tuesday that United Arab Emirates (UAE) authorities continue to hold five prisoners after they completed their sentences up to three years ago, without a clear legal basis.

The five men are Osama al-Najjar, online activist; Khalifa al-Rabea and Othman al-Shehhi, online activists and members of al-Islah (a nonviolent Islamist political movement banned by UAE in 2014 as “terrorist”); and Badr al-Buhairi and Ahmad al-Mulla, activists with ties to al-Islah. Al-Najjar campaigned on Twitter for the release of his father and other detainees as well as criticized a mass trial and conviction of 69 Emirati activists in 2013. Al-Rabea and al-Shehhi were sentenced to five years in prison for their comments on Twitter, supporting scores of political dissidents arrested in 2012. In June 2016 the State Security Chamber of the Federal Supreme Court sentenced Badr al-Buhairi and Ahmad al-Mulla to three years in prison on charges of “joining a secret organization.”

UAE’s Federal Law No. (7) of 2014, “On Combating Terrorism Offences,” appears to permit indefinite detention for persons who deemed to pose “a terrorist threat if said person adopts extremist or terrorist ideology to the extent that he/she seems likely to commit a terrorist offense.” According to HRW, the law “fails to define a terrorist threat clearly” and “sets no time limit for continued detention,” and it is “not clear if the defendant has any right to attend the hearing or see or challenge the evidence used to justify their detention.”

Deputy Middle East director at HRW Michael Page said that the activists “all have lives and families to go back to and should not face the cruel and unlawful prospect of indefinite detention.”