A Syrian human-rights group is calling for the release of an opposition politician who was arrested Saturday. They say his arrest is the latest in a crackdown on pro-democracy and human rights activists, during the past several weeks.

Security forces in Aleppo arrested Samir Nashar of the Free National Party late Saturday. Human-rights groups say no reason was given for his arrest, and they are calling for the release of the 60-year-old politician.

Although police in Syria routinely detain pro-democracy activists for questioning, human-rights campaigners say there has been an upsurge in arrests during the past several weeks.

Writer Ali Abdulla and his two sons have been held since last week, and several other activists are also reported to be in police custody.

Human-rights lawyer and activist Khalil Maatuk says the government is cracking down. He says, "What we have noticed recently is a big deterioration of freedoms in Syria. It was not good before, but it is regressing."

Maatuk says human-rights activists and leaders of the pro-democracy movement are increasingly being brought in for police questioning.

"The security authorities are sending a message to all human-rights activists in Syria," he said. "There are new red lines against any contacts abroad, against demonstrations and against gatherings of more than three people."

The crackdown follows several key events. Earlier this month, human-rights groups organized a protest against Syria's emergency laws. The exiled leader of the Muslim Brotherhood also met with exiled former Vice President Abdel Halim Khaddam, who has become a vocal critic of the regime since fleeing Syria earlier this year.

Finally, a number of the Syrian opposition leaders and activists, including Samir Nashar, attended two recent meetings, in Washington and Paris, with exiled Syrian dissidents and U.S. officials. Attendance at such meetings has now been banned, and some activists have been barred from leaving the country.

The death of longtime-Presdient Hafez al-Assad, and the ascension of his son, Bashar al-Assad, to the presidency in 2001 brought a brief opening of Syrian society and increased tolerance for dissent. But critics say that time appears to have ended.

Aktham Naisseh is a prominent human-rights lawyer, who has been imprisoned and tried for political crimes, although the charges were eventually dropped.

"Syria is now living under police rule that is unbearable, including me, my house was searched two or three days ago," he said.

Naisseh says political freedoms in Syria are returning to the level of the year 2000, before the death of President Hafez al-Assad, when he says oppression was at its peak.

The Syrian government has not commented on the arrest of Samir Nashar. An official at the Syrian Ministry of Information told VOA that everyone who could possibly speak about the matter is out of the country.