The Qatar-based Al-Jazeera TV says Ayman al-Zawahri also urged leaders of Iraq's affiliate and the Nusra Front in Syria to end disagreements and "stop any verbal or actual attacks against one another."
It says al-Zawahri's call came in a letter to the station posted late yesterday. The Britain-based Syrian Observatory for Human Rights, which has activists in Syria, says it also acquired a copy of the letter.
The authenticity of the statement could not be independently verified.