BEIRUT - The Syrian army promised to observe a four-day cease-fire for a Muslim holiday starting Friday, while rebels claimed to have taken control of new areas in the key battleground of Aleppo.
In the announcement read Thursday on state TV, the army granted itself significant loopholes, saying it will respond to rebel attacks or efforts to bolster their positions as well as the entry of fighters into Syria from neighboring countries.
The call for a four-day cease-fire for the Eid al-Adha holiday is currently the international community's only idea on how to try to stop 19 months of violence in Syria. International envoy Lakhdar Brahimi proposed the idea, saying he hopes it will lead to a longer term cease-fire and negotiations between the sides. Brahimi represents the U.N. and the Arab League.
Rebels fighting to topple the regime of President Bashar Assad have no unified command, and rebel reaction to the idea ranged from skepticism that the government would keep its promises to outright refusal.
Abdelbaset Sieda, head of the main opposition group in exile, the Syrian National Council, said he had little faith the regime would hold its fire, but that rebels would respond accordingly.
"We are awaiting the regime side. If they accept it, we will accept it also," he said by phone.
Rebel commanders inside Syria have said in recent days that they did not plan to stop fighting.
The cease-fire pledge came amid rebel claims of major advances in Syria's largest city on Thursday, with the rebels claiming to have seized area long controlled by the regime.
The two sides have been stalemated for months in the fight for Aleppo.
Activists in Aleppo reported heavy clashes citywide on Thursday, particularly around a military airport. Bassam al-Dada, a rebel spokesman, said in a phone interview that anti-regime fighters have taken several areas that have seen months of clashes, including the southwestern neighborhoods of Salaheddin and Suleiman a-Halabi.
Rebels also moved into the northern Kurdish neighborhood of Ashrafiyeh for the first time and were fighting in the areas of Arqoub, Siryan, Zahra and Firqan, al-Dada said.
He said rebels now control more than half of the city and were fighting for control of Aleppo's strategic military base of Nairab.
The Syrian government made no immediate comment on the Aleppo fighting, and rebel forces have often pushed into new areas in the past, only to swiftly withdraw when faced with Assad's air power.
It was unclear if the rebels have the forces to hold the new areas.
An Aleppo activist reached via Skype also said rebels had seized Ashrafiyeh, a Kurdish neighborhood where residents of other city neighborhoods had sought refuge from the fighting.
The activist, who goes by the name of Abu Raed because of security concerns, said the rebels are moving into the neighboring Al-Siryan Al-Jadideh, a Christian area.
"It was a surprise," Abu Raed said on Skype. "It was fast progress and in an unexpected direction."
Abu Raed said he had no information on people killed or wounded in the fighting, but the Britain-based Syrian Observatory for Human Rights said 9 people were killed and 15 wounded when mortars fell on Ashrafiyeh. It said it was unclear who fired them.
Activist also reported heavy shelling and clashes in various rebel districts outside of Damascus, the capital.
Also on Thursday, the deputy head of the United Nations, Jan Eliasson, warned that there are no guarantees that a proposed Syrian cease-fire would hold but urged Syrian rebels and the regime in Damascus to observe it.
"We all have our eyes on the tragedy in Syria, and we pin our hopes now on the cease-fire that hopefully can take place," he told reporters in Geneva.
Previous cease-fire missions have failed, in part because neither Assad nor rebels trying to topple him had an incentive to end their bloody war of attrition. Both sides believe they can still make gains on the battlefield even as they are locked in a stalemate, and neither has faith in negotiations on a political transition.
Al-Dada said the regime could not be trusted.
"Our people have no truce. They have been subjected to massacres," he said.
Associated Press writers Barbara Surk, Bassem Mroue and Karin Laub in Beirut and John Heilprin in Geneva contributed to this report.