Gunshots ring out on the streets of Deraa in southern Syria.
A U.N. statement on Tuesday said more than 3,500 people have been killed since the government's crackdown on protesters began last spring.
Despite an agreement to end the assault against what the government says are "armed gangs", the U.N. and opposition activists say troops loyal to President Assad have continued a bloody campaign of violence against civilians.
Syria agreed to an Arab League peace plan on November 2 - pledging to pull its military from restive cities, set political prisoners free, and start talks with the opposition, which wants to remove Assad and introduce more democratic freedoms.
Syria's representative to the Arab League said Damascus had "gone a long way" toward implementing the plan, pointing to the release of around 500 detainees last week.
But Arab and Western powers are getting increasingly frustrated with Syria's failure to stop the crackdown.
Travis Brecher, Reuters