Syrian intelligence agencies are running torture centres across the country where detainees are beaten with batons and cables, burned with acid, sexually assaulted, and their fingernails torn out and later forced fed to them, Human Rights Watch said in a report.

The United Nations has a secret list of top Syrian officials who could face investigation for crimes against humanity carried out by security forces in their crackdown against an anti-government uprising, a panel of UN human rights experts said.