Two Syrian activists have been missing from their home town of Aleppo since 2 November, raising fears that they have been arrested and are being held in secret detention where they may be at risk of torture.The two men, Mohamed Bachir Arab and Ahmed Omar Azoz, were reportedly involved in organizing peaceful protests in Aleppo. They were both in hiding from the Syrian authorities at the time they went missing, after security forces visited their homes.According to sources, Mohamed Bachir Arab was planning to meet his friend Ahmed Omar Azoz on 2 November. The men have not been seen or heard from since.“We are worried that the two activists have been arrested and are being held in secret detention, not only because of the recent interest the Syrian security forces have shown in them, but also because there has been a widespread pattern of activists being whisked off the streets and held in isolation from the outside world. The authorities should immediately disclose any information they have about their whereabouts,” said Philip Luther, Amnesty International’s acting director for the Middle East and North Africa.“If Mohamed Bachir Arab and Ahmed Omar Azoz have indeed been arrested, they must be allowed contact with their families and given access to a lawyer immediately,” he said.Mohamed Bachir Arab, a doctor, went into hiding around six months ago after security forces raided his home while he was out and confiscated his computer. He reportedly spent 11 months in prison in 2004, after organizing demonstrations at his university in Aleppo.Ahmed Omar Azoz went into hiding at the end of October this year, after members of the security forces came looking for him at his home.Amnesty International has obtained the names of more than 3,000 people reported to have died or been killed during or in connection with pro-reform protests in Syria since mid-March. Many are believed to have been shot by security forces using live ammunition while participating in peaceful protests or attending funerals of people killed in earlier protests.Thousands of other people have been arrested, with many held incommunicado at unknown locations at which torture and other ill-treatment are reported to be rife.Following an action plan agreed with the League of Arab States on 30 October 2011, the Syrian authorities pledged on 2 November to withdraw its troops from restive cities, free prisoners held in connection with the current events, and start talks with opposition groups. Later, on 5 November, it announced that 553 detainees had been released on that day. However, arrests of protesters and perceived supporters of the protests have continued since.