Al-Qaida in Iraq says it has united with a Syrian jihadist group fighting to oust President Bashar al-Assad.
An audio message from al-Qaida in Iraq leader Abu Bakr al-Baghdadi, posted on Islamist websites Tuesday, says his group has been funding cells from Syria's al-Nusra Front. The combined groups, the message says, will be called the Islamic State of Iraq and the Levant.
The statement could not immediately be authenticated.
The al-Nusra Front achieved prominence early last year when it claimed responsibility for several powerful bombings in the Syrian capital and the northern city of Aleppo.
The link between al-Nusra and al-Qaida had been suspected, leading the United States in December to designate the al-Nusra Front a terrorist group.
Baghdadi's declaration came a day after an al-Nusra-style suicide car bomb attack in the heart of Damascus killed at least 15 people and wounded more than 100 others.
Syria's National Coalition opposition grouping Tuesday condemned the bombing, saying the government bore responsibility for the blast.
U.S. Secretary of State John Kerry said he would meet members of the Syrian opposition in London later this week, adding that Washington is looking to provide more help to opponents of Assad.
Meanwhile, United Nations chief Ban Ki-moon Tuesday called on Syria to approve and cooperate with a U.N. mission to probe the alleged use of chemical weapons in the country's conflict.
The Syrian government on Monday said it would not admit a team of inspectors to investigate reports of chemical attacks throughout the war-torn country.
Syria's government has said inspectors should only visit Khan al-Assal near Aleppo, where it alleges the rebels used chemical weapons last month.
Ban has said an investigating team is ready to deploy in Syria within 24 hours.