Syrian regime forces reiterated their pledge Thursday to observe a four-day cease-fire in honor of the Eid holiday, but doubts remain about the truce being obeyed in full after rebel fighters made advances into regime-held areas of Aleppo, the country's largest city.

According to the Associated Press, troops loyal to the Assad regime agreed to follow the U.N.-backed plan, which was noticeably devoid of specifics as to when it would officially begin and who would be monitoring the situation. U.N.-Arab League envoy to Syria Lakhdar Brahimi, who came up with the proposed cease-fire, was also vague about what would happen after the four days.

The proposed truce was officially endorsed by Russia and Iran, among the last members of the community of nations to support the Assad regime, and by both the the government and main rebel organization. As Reuters reports:

 

"'On the occasion of the blessed Eid al-Adha, the general command of the army and armed forces announces a halt to military operations on the territory of the Syrian Arab Republic, from Friday morning ... until Monday,' an army statement read on state television said.

 

It reserved the right to respond if 'the armed terrorist groups open fire on civilians and government forces, attack public and private properties, or use car bombs and explosives'.

It would also respond to any reinforcement or re-supplying of rebel units, or smuggling of fighters from neighboring countries 'in violation of their international commitments to combat terrorism'.

Qassem Saadeddine, head of the military council in Homs province and spokesman for the FSA joint command, said his fighters were committed to the truce.

'But we not allow the regime to reinforce its posts. We demand the release of the detainees, the regime should release them by tomorrow morning,' he said."

During Thursday's fighting, rebels made gains in areas of northern Aleppo that had previously been regime strongholds. Rebels first took over parts of the city in July, but neither side has been able to establish a dominant position over the last several months of fighting. A significant rebel advance in Aleppo could dramatically change the state of the conflict, meaning that Thursday's offensive is not likely to go unchallenged over the next four days.

Residents of the Hajar-al-Aswad neighborhood in the capital city of Damascus reported shelling by regime forces Thursday, but had no confirmed casualties. The Syrian Observatory for Human Rights reported 20 deaths around Damascus, with the bulk of them in the suburb of Duma.

The U.N. hopes to use any window of relative peace made possible by the cease-fire to provide aid to previously unreachable people. As Reuters reports:

"The U.N. refugee agency UNHCR said that it had prepared emergency kits for distribution for up to 13,000 families - an estimated 65,000 people - in previously inaccessible areas including Homs and the northeastern city of Hassaka.

'We and our partners want to be in a position to move quickly if security allows over the next few days,' UNHCR Syria Representative Tarik Kurdi in Damascus said in a statement."

Both President Obama and his challenger Mitt Romney have called for Assad to leave, but in their foreign policy debate Monday night, neither endorsed a U.S.-backed armed intervention into Syria.

Read more of Neon Tommy's coverage of Syria here.

Reach Executive Producer Matt Pressberg here.