Syria has extradited to Egypt one of its most wanted men, the former chief of the country's largest radical group, which gained notoriety for a tourist massacre in 1997, an Islamic pressure group has said.
"The Syrian regime has committed a criminal act that contradicts basic human rights, by handing over Egyptian Islamist Mr Refaie Ahmed Taha to the dictatorial regime in Egypt last month," the Islamic Observation Center (IOC) said.
"Taha was arrested in Damascus several months ago, days after his arrival from Khartoum," the London-based group added in a statement.
Syrian and Egyptian officials were not immediately available for comment.
Analysts said they had believed Taha, who would be the most senior Islamist extradited to Egypt in recent years, was hiding in Afghanistan, and were surprised by the alleged Syrian and Sudanese links.
Mr Taha, 47, headed al-Gama'a al-Islamiya (Islamic Group) when its members killed 58 foreign tourists and four Egyptians in the southern resort of Luxor in 1997.
He had already been sentenced to death in absentia in the early 1990s by a military court, whose verdicts cannot be appealed, for extremist activities. Mr Taha was considered among Egypt's most influential Islamists in exile.
In 1997, Mr Taha appeared on an official list of leading Muslim militants wanted by Egypt. He is not on a US list of alleged terrorists issued after the September 11th attacks on New York and Washington.
The IOC is run by Egyptian Yasser el-Serri, himself sentenced to death by an Egyptian military court for extremist Islamist activities.