Rebels fought along a street in the Salaheddin district of Aleppo on Sunday.
BEIRUT, Lebanon – Both the Syrian government and its opponents claimed victories in the embattled city of Aleppo on Monday, a day after the United Nations humanitarian chief warned of a growing crisis in the country’s largest city, saying that almost of a tenth of its residents had fled over two days of fighting.
Opposition fighters said that after a pitched battle with the army lasting several hours, the rebels had seized control on Monday of a vital checkpoint a few miles northwest of the city, freeing up a route for supplies and fighters between Aleppo and the Turkish border. Opposition activists said that fighters had seized several tanks and other military vehicles. Activists said video posted on Monday showed scenes of the nighttime battle as well as the checkpoint under rebel control.
It seemed doubtful, however, that the rebels could hold the checkpoint, with the Syrian warplanes and helicopter gunships still in control of the skies.
As rebels claimed a victory, Syrian state television reported that the army had won back control of Salaheddiin, a district in the southwest part of the city where rebel fighters had concentrated their attack on government troops. A military officer, speaking to the channel, said that the “mercenary gunmen” had been routed.
Opposition commanders, though, asserted that they had repelled a succession of government attacks. The dueling assertions of progress in the latest front of the bloody conflict could not be immediately verified.
Fluid fighting and competing claims came as Valerie Amos, the United Nations humanitarian chief, called on the combatants to “ensure that they do not target civilians.” In a statement released on Sunday, Ms. Amos said about 200,000 people had already fled the fighting in Aleppo and surrounding areas. “It is not known how many people remain trapped in places where fighting continues today.”
As the Syrian government moved to retake areas of Aleppo, the country’s foreign minister, on a visit to Iran on Sunday, blamed Saudi Arabia, Qatar and Turkey for the escalation of violence and vowed that his government would rout the rebels fighting the army in Aleppo.
“Their plots will fail,” said the minister, Walid al-Moallem. But, he added, that would not stop the “campaign on the international stage against Syria.”
Mr. Moallem made his remarks as the Syrian government continued to pound neighborhoods in Aleppo. In recent days, as opposition fighters have moved to gain control of Aleppo’s neighborhoods, the government has sent armored columns, troops and helicopters to meet them — preparing, residents fear, to move into the city.
On Sunday, activists reported more clashes, including in the Salaheddiin district, but said there had been no mass assault by the army, many of whose troops remained stationed on the city’s outskirts, witnesses said.
Instead, activists said they had noted a change in tactics, saying that the government was using helicopters and artillery to attack several neighborhoods, rather than the tanks that had been deployed in an assault on Salaheddiin and other areas on Saturday.
Rebel commanders said they had destroyed several tanks. A Reuters reporter in Aleppo on Sunday reported seeing at least one heavily damaged tank and another one that appeared to have been captured intact.
Witnesses reported seeing entire neighborhoods emptied of residents, shops that had been closed and hospitals that had no doctors. Video posted on the Internet claimed to show a factory fire in Aleppo, a city that has been Syria’s commercial capital. Residents were seen cheering in another video as what was said to be a captured tank paraded through the streets. More than a dozen people were killed in the fighting, according to antigovernment groups. Agence France-Presse reported that Pierre Torres, a freelance journalist who had done work for the news agency, was wounded in the fighting and evacuated to Turkey on Sunday.
Mr. Moallem’s visit to Iran, one of Syria’s few remaining allies, underscored the pressure on his government as it fights a growing armed insurgency on several fronts. Emboldened by a bombing in Damascus this month that killed four senior government officials, rebel fighters have tried to gain ground in Syria’s largest cities — Damascus, the capital, and Aleppo — testing the strength and reach of President Bashar al-Assad’s army.
The conflict in Syria has increasingly drawn in foreign powers.
As Syria’s international isolation has grown, Western nations have accused Iran of continuing to provide Mr. Assad’s government with weapons and other support. Russia, which has said it has suspended weapons sales to Syria, remains Mr. Assad’s staunchest defender, blocking international efforts to remove him from power.
On the other side, Saudi Arabia and Qatar have led an effort to arm Mr. Assad’s opponents. Turkey is said to have allowed weapons to move over its border, and United States intelligence officials have helped select the recipients, according to American officials.
Mr. Moallem played down the domestic opposition to his government, saying that despite the “plot” by those countries — led, he said, by Israel — Syria did not need foreign help to defend itself.
At the same time, the leader of an opposition group suggested Sunday that the rebels would need heavier weapons.
“The rebels are fighting with primitive weapons,” said the leader, Abdelbasset Sida of the Syrian National Council, according to Reuters. “We want weapons that we can stop tanks and planes with.”
Hwaida Saad and Dalal Mawad contributed reporting from Beirut, and an employee of The New York Times from Aleppo, Syria.
