UAE sentences 'jihadi teenager' to death for joining IS
The 19-year-old, who is thought to be in Syria and who was identified only by his initials KSA, was sentenced in absentia.
Two other defendants were sentenced to seven years in prison by the state security court in Abu Dhabi for planning to join IS, according to national news agency WAM.
They were reportedly planning to travel into Syria to join up with the extremists.
A fourth defendant, also Emirati, was sentenced to three years in relation to the same case.
The defendants denied the charges in court at a hearing last year.
The UAE is part of a US-led coalition that has been carrying out air strikes against the Islamic State group in Syria since September 2014.
The UAE recently adopted tougher anti-terror legislation and introduced the death penalty for crimes linked to religious hatred and being associated with "takfiri" radical Islamic groups.
These measures were taken a week after an Emirati woman, convicted of the extremist-inspired murder of a US schoolteacher, was put to death by firing squad.
Facebook 'insult' lands Palestinian in prison
Separately, the UAE Federal Supreme Court sentenced a Palestinian man to three years in prison, after convicting him of insulting the UAE on social media.
Mohammed Ashour, 38, was found guilty of creating a Facebook page that "damaged the reputation of the country". As well as his jail term, Ashour was fined Dh50,000 ($13600).
The judge also ordered the Facebook page in question to be shut down.
Ashour was tried under the UAE’s cybercrime law, which provides legal basis for prosecuting people who use information technology to criticize senior officials, argue for political reform or organize unlicensed demonstrations.
Although some articles are aimed at preventing the propagation of racist or sectarian views online, the prime effect of the law is to implement severe restrictions on the use of blogs and social networking sites.
People found guilty of committing a cyber crime could face up to life imprisonment and/or a fine varying between Dh50,000 and Dh3 million ($817,000).
Ashour will be deported after serving his sentence.