The trial of 94 Islamists accused of plotting to seize power in the United Arab Emirates began Monday in the absence of rights activists and foreign reporters, who were barred from the court.
The state security court, part of the Federal Supreme Court, convened in Abu Dhabi to try the activists arrested between March and December last year, the interior ministry said in a statement carried by WAM state news agency.
Ten of the defendants are being tried in absentia, while 13 are women, it said, adding that the first hearing was "procedural," and was attended by representatives of local press and Emirati civil society groups.
The accused are said by prosecutors to be linked to the Al-Islah group, which has ties with the outlawed Muslim Brotherhood.
UAE attorney general Salem Kobaish last month said the defendants would be tried for "having created and led a movement aimed at opposing the basic foundations on which the state's political system is built and at seizing power".
The group had formed a "secret organisation" which was in contact with individuals and organisations "abroad", including the Muslim Brotherhood, Kobaish said.
The attorney general said they had also created or invested in real estate companies to finance their organisation.
The hearing was adjourned to March 11, the ministry said.
Relatives posted pictures on Twitter of representatives of human rights organisations standing outside the court building after allegedly being denied entry as observers.
Authorities bused in relatives authorised to attend the hearing, banning them from driving on their own to the court building, as security measures were very tight, activists said on Twitter.
Amnesty International said a Kuwaiti lawyer representing it as an observer was denied entry into the UAE.
"By denying access to observers from human rights groups, the UAE authorities are blatantly trying to manage what information is made available about the trial to the outside world," Amnesty International said.
The Kuwaiti lawyer, Ahmad Nashmi al-Dhafeeri, wrote on his Twitter account that he was sent back from the airport.
"I was prevented today from entering the UAE to monitor the trial of those accused of plotting to overthrow the government as a delegate for Amnesty International," Dhafeeri wrote on his Twitter account late Sunday.
The UAE, a federation of seven emirates led by oil-rich Abu Dhabi, has not seen any of the widespread pro-reform protests which have swept other Arab countries, including fellow Gulf states Bahrain and Oman.
But authorities have stepped up a crackdown on voices of dissent and calls for democratic reform.
Dubai police chief General Dahi Khalfan has accused the Muslim Brotherhood -- which came to power after the uprisings in Egypt and Tunisia -- of plotting against Gulf monarchies.
In January, local media announced that UAE authorities had arrested 11 Egyptian residents suspected of links to the Brotherhood. Human Rights Watch later spoke of 13.
The case has sparked a sharp deterioration of relations between Abu Dhabi and Cairo, already under strain since Brotherhood candidate Mohamed Morsi's election as Egyptian president last June.
The Gulf country, where membership of political parties is banned, has rejected a request from Egypt for the release of its nationals.