By Khaled Yacoub Oweis
AMMAN, April 30 (Reuters) - Syrian security forces arrested two veteran opposition figures and a group of female protesters, adding to thousands of political prisoners in the country, rights groups said on Saturday.
The reports came as the Syrian human rights organisation Sawasiah said security forces had killed at least 560 civilians since protests against the authoritarian rule of President Bashar al-Assad started last month.
The organisation, founded by jailed human rights lawyer Mohannad al-Hassani, said the authorities have arrested thousands of pro-democracy sympathisers since the demonstrations erupted in the southern city of Deraa on March 18.
"They are in prisons and detentions already packed with thousands of prisoners of conscience who peacefully defied the repressive regime that has spilt the blood of thousands of Syrians in the last four decades," a statement by Sawasiah said.
Security agents detained Hassan Abdel Azim, 81, of the National Democratic Grouping from his office in Damascus, and Omar Qashash, 85, of the People's Democratic Party, as he was walking in a park in Syria's second city Aleppo, said the Syrian Centre for the Defence of Prisoners of Conscience.
The National Organisation for Human Rights in Syria, headed by prominent rights campaigner Ammar al-Qarabi, confirmed Azim's arrest and said Hazem Nahar, another member of the National Democratic Grouping, had been arrested on Thursday.
"Arbitrary arrest is among the most dangerous threats to the the individual right to freedom. We condemn.. the far-reaching campaign of arrests that Syrian cities have seen in the last several days," the organisation said in a statement.
Other rights campaigners said security forces arrested 11 women who marched in a silent all-women demonstration in the busy Salhyia commercial district of Damascus on Saturday.
The march was in support of residents of the city of Deraa, where the government has sent tanks to crush an uprising.
About 50 women managed to briefly raise signs that said "Break the Deraa siege" and "No to the killings" before they were confronted by security forces.
The security police accused them of being "spokeswomen for the United States and Israel". One woman shouted back: "When men fall quiet, women speak out" as she was being led away, one rights campaigner who was at the scene said.
Separately, human rights lawyer Razan Zaitouneh said secret police raided her home in the Qazazine district of Damascus on Saturday while she was not there.
"They waited for me and for my husband for hours then they arrested my husband's brother Abdelrahman Hamidi, who was the only person in the house at the time," Zaitouneh said.
(Reporting by Khaled Yacoub Oweis; Editing by Matthew Jones)