"The spiral of violence, the lack of proportion in the regime's reactions, its incapacity to protect the civilian population, mean that the regime's days are numbered, but will it fall in a week or in a year? That is a question I do not dare answer," he told the AFP news agency.

Mood characterised the fight between the rebels, who are fragmented into several different factions, some of whom are armed, and the country's military as a case of "David versus Goliath".

He said that a rebel success in achieving the resignation of Assad, their stated objective, would not necessarily lead to the end of the conflict.

"Many think that if Bashar al-Assad falls or that if he is given an honourable exit... the problem will be solved. That is an over-simplification one should be wary of," Mood told a news conference.

"The situation could even get worse," he cautioned.

"On the other hand, it is important to say that it is impossible to imagine a future Syria with the current power holders still in place."

"Every time there are 15 people killed in a village, 500 additional sympathisers are mobilised, roughly 100 of whom are
fighters," Mood said.

He cautioned, however, that the conflict "could last for months or even years". 

Mood has now been replaced in Syria by Lieutenant General Babacar Gaye, a Senegalese military officer who is taking over a drastically reduced mission of just 150 observers. Lt-Gen Gaye's mission has a mandate of only 30 days.

-Aljazeera-