Hopes of Syria opening up have been dashed since 2000

All the board members of the Jamal Atassi Forum for National Dialogue were taken from their homes at dawn.

Activists said the arrests were reminiscent of the 1980s when arbitrary detentions and political repression were the norm under Hafez al-Assad.

The forum was one of several set up after his son Bashar took power in 2000 - but the only one still working today.

Extremism

A Syrian official quoted by AFP news agency said the eight had "used the forum to disseminate the ideas of the Muslim Brotherood", which is outlawed in Syria.

"Syria is open to dialogue between all strands of patriotic opinion, but not extremism and only in accordance with the law," the official said.

The Atassi Forum, which calls for broader political participation in Syria, is named after a leading communist intellectual and dissident.

His daughter Souheir was one of two women arrested in Tuesday's round-up.

"We hope that they are arrested for investigation only," said Ammar Qurabi of the Arab Organisation of Human Rights in Syria.

Last week, the authorities arrested Ali Abdallah, a writer who had read a statement in the name of the Muslim Brotherhood during a debate at the Atassi Forum.

On Sunday, Muhammad Radoun, the head of an unofficial human rights organisation, was also arrested soon after his group had condemned the recent arrests of several Islamists.