(CNN) -- The Syrian government is freeing some activists while arresting hundreds of others in its back-and-forth bid to placate protesters and crush dissent, a human rights lawyer said.
Attorney Razan Zaytouni sent CNN a list Sunday naming more than 500 people she said have been arrested since the start of the unrest a couple of weeks ago. Roughly half of those people have since been released, the list shows.
CNN could not independently confirm details of the report. Last week the Syrian Arab News Agency said that a wave of arrests came as government security forces were searching for members of an "armed group" that killed "a number of citizen and security forces."
SANA reported that an unidentified official said snipers from the group fired at citizens and security forces from rooftops. This is disputed by activists and eyewitnesses who told CNN that government snipers fired shots at unarmed protesters and government forces beat demonstrators.
Protesters in Syria are upset at what they see as the nation's heavy-handed rule. Opponents of the government allege massive human rights abuses and are calling for political and economic reform. They also want the release of all political prisoners and an end to emergency law.
The emergency law allows the government to make preventive arrests and override constitutional and penal code statutes. In effect since 1963, it also bars detainees who have not been charged from filing court complaints and from having a lawyer present during interrogations.
Zaytouni said she is part of a group of lawyers that has volunteered to help defend political prisoners.
"But our role is superficial. There is no judicial system in Syria and the security apparatus arrests people and send them to courts directly," she said.
Amnesty International estimated late last month that at least 93 people were believed to have been arrested by Syrian security forces between March 8 and March 23 and held in unknown locations.
The real number arrests is likely to be "considerably higher," the rights group said, adding that the detained include students, intellectuals, journalists and activists.
Zaytouni spoke the same day the family of an imprisoned activist said he was freed.
Mohammad al-Abdallah told CNN his brother was released Sunday after more than five years in prison. Omar al-Abdallah, 26, was accused of "taking actions and making threat(ening) statements against the state in Syria," his brother said.
Their father remains a political prisoner, he added.