( CNN ) -- The United Nations suspended all activities in Syria on Saturday due to the escalating levels of violence , the head of the global body 's mission said . `` There has been an intensification of armed violence across Syria over the past 10 days , '' said Gen. Robert Mood , head of the U.N . Supervision Mission in Syria . `` This escalation is limiting our ability to observe , verify , report as well as assist in local dialogue and stability projects -- basically impeding our ability to carry out our mandate , '' Mood said . The situation , Mood said , was too high risk . 'Choking siege ' leaves Syrian town in crisis . The U.N. monitors , whose number gradually rose to about 300 , were sent in to ensure that both President Bashar al-Assad and opposition fighters were abiding by a six-point peace plan brokered by special envoy Kofi Annan . A ceasefire took hold April 12 but only nominally , it turned out . Violence has soared in recent days with reports of heavy government bombardment of town and chilling massacres of civilians . On some occasions , the monitors themselves have come under fire . `` The lack of willingness by the parties to seek a peaceful transition , and the push towards advancing military positions is increasing the losses on both sides : innocent civilians , men women and children are being killed every day , '' Mood said . He said U.N. observers will no longer be conducting patrols and will stay in their locations until further notice . This suspension will be reviewed on a daily basis , Mood said . Operations will resume when we see the situation fit for us to carry out our mandated activities . Syrian opposition groups estimate that between 12,000 and 14,000 people have died in the months of uprising against al-Assad 's rule .
The United Nations says Syria poses too much of a risk for observers . The head of the mission says violence has intensified in the last few days . The escalation is limiting the ability of observers to do their work . The monitors went in to monitor compliance to President Annan 's peace plan .