Abu Dhabi, United Arab Emirates (CNN) -- As judges heard testimony Sunday in the trial of five activists charged with publicly insulting top United Arab Emirates officials, family members of four of the accused made a plea for their release.
"We turn to you asking for your interference, with your influence, in order to stop this trial that isn't consistent with international standards for fair trial," family members said in a letter asking for help from Abu Dhabi's crown prince and the United Arab Emirates' president and vice president.
The letter, which was distributed by a defense attorney after Sunday's hearing, accused judiciary, prosecution and prison officials of violating 20 international human rights standards.
Human rights groups have named the five activists, arrested in April, as Ahmed Mansoor, an engineer and blogger; Nasser bin Ghaith, an economist and university lecturer at Sorbonne Abu Dhabi and advocate for political reform; and online activists Fahad Salim Dalk, Ahmed Abdul-Khaleq and Hassan Ali al-Khamis.
Sunday's letter was signed by family members of Mansoor, bin Ghaith, Dalk and Abdul-Khaleq.
The activists also have been charged with committing acts that pose a threat to state security, undermining public order, opposing the government system and instigating others to break laws, according to a statement previously released by UAE's attorney general.
The attorney general has not offered specifics of the alleged acts, and United Arab Emirates officials have repeatedly declined requests from CNN for comment about the case.
They face up to five years in prison if convicted, according to human rights groups.
Defense attorneys called a witness at Sunday's hearing and requested more time to make their case. Judges decided to adjourn the trial until October 23.
Christoph Wilcke, a representative of Human Rights Watch who observed Sunday's hearing, said he had seen some improvements in how authorities were handling the case, such as opening court sessions to the public and the media.
"But it has a long way to go, in particular when it comes to the evidence at hand," he said. "The ability for the defense to cross examine witnesses and have time to meet and discuss with their clients the accusations at hand ... has not happened as far as we know."
The trial drew a group of pro-government demonstrators to the courthouse in Abu Dhabi Sunday. Men carrying placards and pictures of Emirati leaders marched, chanting slogans in support of the United Arab Emirates.
"When you have a law, you have to comply with ... whatever the law says. If you want to do something beyond the law, you have to do your best to request a change in that law, but don't do things according to your mood," said Ahmed Jomaa Al-Hosany, a businessman who said he supported the government.
But one demonstrator outside the courthouse said she supported the defendants. Nour Mubarak said the defendants had been jailed because of their opinions.
"It's time for our country to free them and listen to our opinions and our requests in participating in this country," she said.
Human Rights Watch contends the five are on trial for using the online political forum UAE Hewar.
"None of the messages allegedly posted by the accused to the banned site do more than criticize government policy or political leaders," according to the group, which said it reviewed the posts. "There is no evidence that the men used or incited violence in the course of their political activities."
The group contends freedom of speech is guaranteed by the UAE constitution.
"Every moment that these men spend behind bars simply for exercising their right to free speech is a miscarriage of justice," said Sarah Leah Whitson, Middle East director at Human Rights Watch.
Attorney Mohammed al-Roken, who represents two of the defendants, recently told the courts the accused have been treated worse than convicts, and have been forced to constantly wear handcuffs.
"How can they pray or eat or go to use the bathroom with handcuffs on?" al-Roken asked.
But some Emiratis support the government and feel the activists are getting what they deserve. Lawyer Faiza Mousa pointed out that the defendants have a debt to the UAE's rulers.
"All of them, they are using this country. They are living here. They take the education free. They finish their master degree and some they have their Ph.D. From where? From their pocket money? No, from this country's money. They are living now in their houses -- from their money? No. From this country 's money. So they got everything free," she said.
Poet Abdul-Kareem Al-Marzooqi added that there are some basic differences between Emirati culture and European culture.
"We cannot talk badly or joke against your father, against your mother, against your brother, against your neighbor also," Al-Marzooqi said. "You must be polite and talk politely. How with the ruler? The ruler is more important . For that, we care about people. Please stop. This is (a) red line."