Pro-democracy activists say bloody clashes erupted in several Syrian cities on Friday as hundreds of thousands of protesters took to the streets.
Syrian security forces killed at least 12 demonstrators in Hama and Deraa. Five government troops were also shot dead.
Video footage from the city of Homs shows the convoy of vehicles belonging to monitors from the Arab League being halted by the sheer weight of demonstrators.
The monitors are continuing to evaluate Syria’s commitment to peaceful reform.
Amateur video from the city of Idlib shows the monitors in yellow safety vests wading through a sea of people on foot.
Activists say they were keen to show the strength of their movement.
The London based Syrian Observatory for Human Rights claims as many as 250,000 people took part in rallies in Idlib and Hama provinces on Friday.
Other massive protests were held in the Daraa province and the Damascus suburb of Douma.