“The mission will happen in a week’s time or so,” Swedish scientist Ake Sellstrom said in an interview with UN Radio yesterday. “It’s a matter of days.”

Mr. Sellstrom was appointed by Secretary-General Ban Ki-moon to head the UN fact-finding mission, which was launched following a formal request from the Syrian Government.

The initial focus of the investigation will be an incident involving the alleged use of chemical weapons in Kfar Dael region in Khan Al-Asal area in Aleppo governorate.

“The investigation mission is to look into the specific incident brought to my attention by the Syrian Government,” Mr. Ban said last week when he announced the investigation. “I am, of course, aware that there are other allegations of similar cases involving the reported use of chemical weapons,” he added.

Mr. Sellstrom, currently a project manager at a Swedish research institute, said that the members of the mission will consist of international organizations and that they have all been nearly chosen.

“There’s a lot of preparatory work,” he noted. “Then we also have to rely on the security situation to allow us to do the mission.”

Following the preparatory work, the mission will have three or four days of inspections, and then two to three weeks of report writing and chemical analysis, he added.

UN spokesperson Martin Nesirky, speaking at a news conference in New York today, reiterated that the investigation is of a very specific nature.

“It is not the role of this mission to apportion responsibility or blame,” he stated. “It’s not a criminal investigation. It’s looking at whether chemical weapons were used, and not by whom.

Opposition groups, meanwhile, have insisted that the Syrian regime itself used such weapons.

“The investigation mission is to look into the specific incident brought to my attention by the Syrian Government,” the Secretary-General told journalists in New York this morning.

“I am, of course, aware that there are other allegations of similar cases involving the reported use of chemical weapons,” he added.

Mr. Ban said the investigation will start “as soon as practically possible.”

He said his senior advisers are working on the modalities in close consultation with the relevant bodies, including the Organization for the Prohibition of Chemical Weapons (OPCW) and the World Health Organization (WHO).

Detailed issues such as overall mandate, mission composition, and operational conditions, including safety and security, would be considered in those discussions, he said.

“In discharging its mandate of an investigation mission, full cooperation from all parties will be essential,” Mr. Ban said, stressing that “this includes unfettered access.”

The UN received a formal request from Syrian authorities yesterday for a “specialized, impartial and independent mission” to investigate the alleged use of chemical weapons.

Speaking to reporters at UN Headquarters yesterday afternoon, Syrian Ambassador Bashar Ja’afari said that he wanted a probe to look into the use of those weapons by “armed terrorist groups” in an attack on the village of Khan al-Assal on the outskirts of Aleppo on 19 March.

If requested by a Member State, Mr. Ban said he has a mandate to consider conducting an investigation on alleged uses of chemical, biological and toxin weapons pursuant to General Assembly resolution 42/37 C of 1987 and reaffirm by Security Council resolution 620 of 1988.

“My announcement should serve as an unequivocal reminder that the use of chemical weapons is a crime against humanity,” Mr. Ban reiterated in his press encounter.

He also repeated that a political solution is needed in Syria, and called on the regional and international community to find unity and support the efforts of his Joint Special Representative, Lakhdar Brahimi.

Since the uprising against President al-Assad began in March 2011, more than 70,000 people, mostly civilians, have been killed and more than three million displaced. In addition, some 1.1 million people have taken refuge in neighbouring countries.