The UN Human Rights Council has appointed three experts who are to examine human rights violations in Syria, as mandated during an August session.
The panel includes Yakin Erturk of Turkey, Sergio Pinheiro of Brazil, and Karen Abu Zeid of the United States.
The 47-member Geneva forum has asked investigators to establish the facts and circumstances of violations and to identify the perpetrators so that they can be held accountable.
Earlier in the day, UN human rights chief Navi Pillay said at least 2,600 people had been killed in the unrest in Syria since popular protests broke out in March.
Meanwhile, Russia rejected Western calls for greater pressure on President Bashar al-Assad's regime over its crackdown on protests.
President Dmitry Medvedev said recent U.S. and European sanctions on Syria meant "additional pressure now is absolutely not needed in this direction."
In Washington, U.S. State Department spokesperson Victoria Nuland reacted to Medvedev's statement, saying, "We strongly disagree. We believe that it's time for the UN Security Council to take stronger action. We continue to consult in New York. We want a resolution that has sanctions teeth."
Antigovernment Syrian protesters posted a message on Facebook, calling for "day of rage" protests against Russia around Syria on September 13.
The posting said, "We express our anger toward Russia and the Russian government."
compiled from agency reports