Authorities have arrested two human rights activists this week, five Damascus-based human rights groups reported Friday. The five, including the Arab Organization for Human Rights, said in a fax sent to The Associated Press here that they did not know why writers Ali Abdullah and Najat Tayyara were arrested. They condemned what they called the government's reliance on "security solutions" in dealing with opposition, noting the detention of several pro-democracy and human rights activists in recent weeks. It's virtually impossible to confirm such arrests with the Syrian government, which does not comment on security issues. A separate fax sent Friday and signed by Ammar Qurabi of the Arab Organization for Human Rights said Abdullah's son, Omar, was detained March 18. Tayyara, the second writer, was vice president of the Human Rights Association in Syria until some two weeks ago, when he quit that position. Qurabi and another human rights lawyer, Anwar al-Bunni, said Tayyara has been missing since Wednesday night.