plagued Syria for more than six months, as protesters demanding more freedom, democratic elections and an end to al-Assad's regime have been met by brute force. The government has maintained a consistent narrative: It is going after armed terrorists. But opposition activists say the regime is behind a systematic, sustained slaughter. Mattar, 26, was on the run for three months before being taken into custody, according to the Syrian Observatory. The group, citing reports from Mattar's fellow opposition members, said he was tortured to death. Syria's crackdown on protesters has been roundly condemned by many world leaders and the United Nations. The Arab League has publicly called for al-Assad's regime to show restraint and end the violence. The United States has imposed sanctions on Syria, freezing assets of specific regime members and banning Americans from doing business with the country. The European Union banned the import of Syrian oil and imposed a travel ban. Navi Pillay, the U.N. High Commissioner for Human Rights, put the number killed in the unrest at 2,600, citing reliable sources on the ground, in remarks prepared for delivery Tuesday during the commission's session. The Syrian Observatory has said more than 2,000 people -- mostly demonstrators -- have died since the uprising began in mid-March. In her statement, Nuland repeated calls by the United States for