More than 60 people were killed and more than 200 others were injured in a string of bombings across Iraq last weekend. The U.S. State Department offered a $10 million reward for information that would help authorities "kill or capture" Abu Bakr al-Bahgdadi, the leader of the Islamic State of Iraq, al-Qaida's national affiliate.
The State Department said the weekend bombings bore the hallmarks of al-Qaida.
Joe Stork, deputy director of Middle East programs at Human Rights Watch, said there is "clear evidence" of violations of international law by al-Qaida in Iraq.
"No political goal or grievance can possibly justify this widespread and organized murder campaign, which is wreaking terrible suffering on Iraqis," he said in a statement Sunday.
Last month was the deadliest month in Iraq in nearly five years. Gyorgy Busztin, deputy special envoy for Iraq, said the level of violence in Iraq was inhuman.
"All honest Iraqis should unite to put an end to this murderous violence that aims to push the country into sectarian strife," he said in a statement.