The Syrian ceasefire is off to a shaky start. On Friday morning, a four-day ceasefire to mark the Muslim holiday of Eid al-Adha went into effect. The violence had not let up Thursday evening, when a Syrian government artillery barrage was reported in the Hajar al-Aswad neighborhood in Damascus. The ceasefire has been proposed by the joint UN-Arab League envoy for Syria, Lakhdar Brahimi.

"it's important that all sides will adhere to this,” said U.N. spokesman, Martin Nesirky. “We will understand that there is a lack of trust between parties therefore we all understand that we cannot be sure yet what will transpire, but the hope is that the guns will fall quiet for the people of Syria so that they can have peace and quiet during this holy holiday."The UN refugee agency (UNHCR) said it is ready to send thousands of pre-positioned emergency aid packages to families in previously inaccessible areas of Syria.

"In all, some 550 tonnes of supplies are being made available for distribution to up to 13,000 affected families – some 65,000 people – in several previously inaccessible areas," a UNHCR press release said on Thursday. In Aleppo, one of the cities most affected by the violence, the agency has already pre-positioned 5,000 emergency family kits, and it hopes to rush nearly 2,000 more from Damascus to the eastern city of Homs today. Emergency kits will also be made available in the Al Raqqa governorate and areas south of Hassakeh over the weekend. Each emergency family kit contains four mattresses, six blankets, one jerry can, a kitchen set, plastic sheeting and hygiene items, including sanitary napkins and soap.

However, relief agencies are being cautious, since both sides have qualified their support for the ceasefire. The main opposition group the Free Syrian Army is demanding that the al-Assad regime free detainees, and a spokesman said some individual units will decide for themselves whether or not to back the truce. The government, while officially backing the initiative, said it reserved the right to respond to rebel attacks of any kind.

The United Nations is calling on those with influence in the region to use it on all parities, so that a permanent suspension of violence can take place and pave the way for a political solution to the crisis in Syria.

“We and our partners want to be in a position to move quickly if security allows over the next few days,” said the representative of the Office of the UN High Commissioner for Refugees (UNHCR) in the country, Tarik Kurdi. “There are areas around Aleppo, Idlib, Al Raqqa and Homs we have been unable to reach with humanitarian aid for some time. If there is a window of opportunity here, we will be ready to move.”

While in Tehran last week, the UN and League of Arab States Joint Special Representative for the crisis in Syria, Lakhdar Brahimi, had appealed to Iranian authorities to assist in achieving a ceasefire during Eid al-Adha, underscoring that such a move – during one of the holiest holidays celebrated by Muslims around the world – would help create an environment that would allow a political process to develop.

Starting on Friday, the religious observance of Eid al-Adha – or the Feast of the Sacrifice – commemorates the willingness of Abraham to sacrifice his son Ishmael as an act of obedience to God.

UNHCR, which currently has more than 350 staff in three offices across Syria, said it has been working closely with the Syrian Arab Red Crescent and other partners to provide aid. It has also been carrying out an emergency cash assistance programme for displaced people, providing emergency funds for vulnerable families so they can pay rent or meet other critical.

“Despite the immense security challenges, the United Nations and humanitarian partners have managed to scale up and reach areas where people need help, including food for 1.5 million people in September and health assistance to 60,000 people including emergency care for the wounded,” said the Under-Secretary-General for Humanitarian Affairs, Valerie Amos.

“The fighting must stop before more lives are needlessly lost,” she added. “While the humanitarian operation is helping large numbers of people in many areas, it is hindered by lack of funding as well as insecurity and violence.”

More than 20,000 people, mostly civilians, have died in Syria since the uprising against President Bashar al-Assad began some 20 months ago. A further 2.5 million Syrians urgently need humanitarian aid, and over 340,000 have crossed the border to Syria’s neighbouring countries, according to UN estimates.