ISTANBUL — The car bombing of a hotel complex in the eastern Syrian city of Raqqa that the militant group the Islamic State of Iraq and Syria had been using as a barracks for its fighters has brought new attention to the fierce fight splitting rival factions opposed to Syrian President Bashar Assad.
The explosion late Tuesday wounded scores of people, including women and children, and highlighted the complexity of the Syrian battlefield, where the United States has been searching for a moderate rebel group that would be a reliable recipient of military aid. In a speech at the U.S. Military Academy at West Point, N.Y., President Barack Obama said once again on Wednesday that the U.S. was considering ways to assist moderate rebels, but he provided few details.
There are so many fighting factions inside Syria, however, that it was impossible to say which one had targeted the Raqqa hotel complex. Suspects included al-Qaida's official affiliate, the Nusra Front, Kurdish militias battling to secure their portion of Syria, and the Syrian government itself.
Ayman al Tamimi, an analyst of Syrian and Iraqi Islamist extremist groups for the Philadelphia-based Middle East Forum, said that while small-scale attacks on ISIS have become increasingly common, Tuesday's massive explosion marked a major escalation. He said that Nusra, the Kurds or even other local anti-ISIS groups all had ample opportunity and motive.
At least 6,000 rebels have been killed in factional fighting that began in January when rebels from Nusra, another coalition of fighters known as the Islamic Front, and moderate rebels once associated with the U.S.-aligned Free Syrian Army turned on their one-time ISIS allies in a rejection of that group's harsh Islamist rule in the areas of Syria it controlled. The groups succeeded in driving ISIS from Idlib province and parts of Aleppo province, but ISIS cemented its control over Raqqa, driving other rebel groups from the city, which remains the only Syrian provincial capital to have fallen to anti-Assad forces.
In a statement circulated via Twitter, ISIS said the booby-trapped car had been placed adjacent to the Lazord Hotel in the Thakneh neighborhood of Raqaa. The group said the bomb "wounded 45, most of them women and children and a third of them in critical condition." It did not say if people had been killed.
The Syrian Observatory for Human Rights, a Britain-based pro-rebel monitoring group that collects casualty data via a network of activists inside Syria, confirmed the blast, saying it had left "dozens injured, most of them civilians," and led ISIS to order an immediate curfew on Raqqa. The observatory also said that ISIS had undertaken a dragnet operation to arrest potential assailants — either Assad loyalists or members of other rebel groups — who have been quietly conducting an underground campaign of bombings and assassinations against ISIS and the Islamist state it has established in eastern Syria.
The observatory reported that at least 10 fighters from anti-ISIS "Islamic Battalions" — a term often used to describe Nusra or its Islamic Front allies — had been arrested in connection with the blast.
ISIS and its supporters immediately took to Twitter to accuse Nusra of having conducted the operation, even as Nusra denied responsibility.
A Facebook page linked to the Kurdistan Workers Party, a militant organization of Kurdish fighters that is better known by the initials PKK, said the explosion was an operation by the "fedeyeen" of Kurdistan, a militia that has been battling both Nusra and ISIS for control of key areas in northeastern Syria, where the heavily Kurdish population has been quietly establishing a state of its own over the objections of other predominately Arab rebel groups.
The Hasakah Kurdistan News said the explosion was in revenge for a siege that ISIS had conducted on the Kurdish town of Kobani, which sits at a strategic crossroads linking Turkey and Iraq, but the announcement was unofficial and none of the Kurdish militant groups has officially claimed the operation.
Tamimi said it was not surprising that Nusra wouldn't claim the explosion. Even though Nusra is well known for car bomb attacks — it's claimed a series of car bombs in pro-Assad areas in and around the city of Homs that have killed at least 60 in recent weeks — it would be reluctant to be seen as killing ordinary Muslims in an anti-Assad area. "The attack doesn't look good for (Nusra) since children got killed and wounded," he said.
"This car bomb is really unprecedented," said Tamimi, who described a growing campaign by anonymous groups in Raqqa targeting ISIS members with roadside bombs and even direct attacks on ISIS fighters.
He said several groups have surfaced weeks as ISIS' main opponents in Raqqa, including an ex-Nusra affiliate, the Liwa Thuwar Raqqa, and a group known as the Euphrates Islamic Liberation Front. He also noted that three military bases in the area remain under government control and that "there's also a pro-regime underground."
But Tamimi said only Nusra and the Kurds are "capable of launching such a powerful car bomb."