The United Arab Emirates has tightened its law on internet use, making it a criminal offence to mock its rulers or organise unauthorised demonstrations.
A presidential decree says anyone who creates or runs a website or uses the internet to deride or damage the state or its institutions faces imprisonment.
The institutions include the rulers and senior officials across the federation of seven semi-autonomous Gulf emirates.
Activists have criticised the move as an attempt to limit freedom of speech.
The UAE has not experienced the unrest seen elsewhere in the region.
However, since March the authorities have detained without charge more than 60 civil society activists, some of whom have ties to Islah - a local group that advocates greater adherence to Islamic precepts - including human rights lawyers, judges and student leaders.
The authorities have also been accused of deporting and harassing human rights defenders, denying legal assistance to political detainees, and intimidating and deporting lawyers seeking to assist detainees.
Government and police officials have said the crackdown is a response to a foreign-inspired Islamist plot that aims to overthrow the government.
The amendments to the UAE's existing law on internet crime were announced on Tuesday in a decree by President Sheikh Khalifa bin Zayed Al Nuhayyan, the ruler of Abu Dhabi.
Many of the measures focus on issues such as online fraud, privacy protection, and efforts to combat prostitution, pornography and gambling. However, a major section imposes restrictions on online dissent.
The legislation now stipulates "penalties of imprisonment on any person who creates or runs an electronic website or uses any information technology medium to deride or damage the reputation or stature of the state or any of its institutions," according to the state news agency, WAM.
The minimum prison sentence will be three years, according to Abu Dhabi-based newspaper, The National. Foreign nationals will meanwhile be deported, it added. The UAE has nearly four million migrant workers.
The institutions include the president, vice-president, any of the rulers of the seven emirates, their crown princes and deputy rulers, as well as the national flag, national anthem, or any of symbols of the state, it said.
The law also prohibit "information, news, caricatures or any other kind of pictures" that authorities believe could threaten security or "public order".
This includes posts calling for "demonstrations, marches and similar activities without a licence being obtained in advance from the competent authorities" or "disobeying the laws and regulations of the state".
Those responsible for posts which "display contempt" for Islam or any other religion could also be jailed.
The decree was issued by Sheikh Khalifa just hours after the UAE was elected to a three-year term on the United Nations Human Rights Council.