Damascus: Syrian authorities have ordered internet cafe users to reveal their identity, the latest measure in their "iron censorship" of cyberspace, a Syrian monitoring group said on Thursday.

Security officials ordered internet cafe owners this week to take down the names and identification cards of their clients as well as the times they come and leave, Mazen Darwich, head of the Syrian Media Centre, told Reuters.

The records are to be presented regularly to the authorities, who targeted bloggers in recent months as part of a renewed campaign against dissent.

"These steps are designed to terrorise internet users and spread fear and self censorship in violation of the right to privacy and free expression," Darwich said.

"The government has been methodical in extending the scope of its iron censorship," he said.

There was no comment from the government. Officials had said internet controls were needed to guard against what they described as attempts to spread sectarian divisions and "penetration by Israel".

Several Internet cafes confirmed the new regulations. Restrictions have also increased on surfing the web and online publishing. An increasing number of Syrians who have voiced opinions on the internet were being jailed, Darwich said.

The Syrian Media Centre, an independent body that tracks curbs on media, said at least 153 internet sites are blocked in Syria, with plans to block Googleblog and the Arab Maktoobblog.

"Open forums have been used by thousands of Syrians to launch a counteroffensive against the government's curbs on public expression," Darwich said.

Facebook and YouTube are already banned as well as sites for Syrian opposition parties and Lebanese newspapers. The site of the Saudi Asharq Al Awsat newspaper is blocked although the daily has a correspondent in Damascus.