HOMS, Syria — With a gigantic explosion, Syrian rebels on Thursday leveled a historic hotel being used as an army base in the northern city of Aleppo by detonating bomb-packed tunnels beneath it, activists and militants said.
The blast near Aleppo's medieval citadel, an imposing city landmark that was once swarming with tourists, killed an unknown number of soldiers. It turned the Carlton Hotel, known for its elegant architecture and proximity to the citadel, into a pile of rubble.
The attack was a powerful statement that the rebels could still deal heavy blows elsewhere in Syria even as they withdrew from Homs, surrendering that city to President Bashar Assad's forces.
In Homs, 95 miles south of Aleppo, army troops were poised to enter the city's old quarters after hundreds of fighters complete their evacuation, which was suspended after gunmen in northern Syria prevented trucks carrying aid from entering two villages besieged by rebels. The aid delivery was part of the cease-fire agreement allowing rebels to leave Homs for rebel-held areas farther north.
An Associated Press journalist who visited Homs on Thursday reported massive destruction. Standing near the city's main square, known as the Clock Square, the streets appeared almost apocalyptic. Even the trees were burnt.
Meanwhile, the destruction of the Assad regime's stockpile of chemical weapons is still incomplete.
The final 8 percent of Syria's chemical weapons stockpile that has yet to be exported -- about 100 tons -- remains inaccessible because it is stored near an area held by insurgents, the United Nations official overseeing the arsenal's destruction said Thursday.
The official, Sigrid Kaag, said that removal experts would need "less than a working week" to extricate the material once they gain access to the site, which is near Damascus. In all, there are five containers of the most dangerous substances there, and 11 containers of other chemicals needed for the weapons.
"We do need that final push to achieve that 100 percent," Ms. Kaag told reporters at the U.N. in New York City.
Under a Security Council resolution, the arsenal must be destroyed by June 30. Critics of Assad's government, led by the U.S., have accused him of stalling the removal of the final batch of chemicals, which are to be placed aboard ships from Norway and Denmark at the Syrian port of Latakia.
She gave no indication that the June 30 deadline was in danger, but there has been growing speculation that it may have to be pushed back.
The New York Times contributed.