Syrian activists have accused the government of manipulating and deceiving Arab League monitors.
Protesters say that the regime has replaced or painted over military vehicles to give the illusion that the army has withdrawn from city centres, as well as changing signposts and directing the monitors to areas loyal to Assad.
Around 100 monitors are in the country to oversee the government's compliance with an Arab League peace plan.
The UN says more than 5,000 people have been killed in the unrest since March 2011,
"The observers are going to areas known to be loyal to the regime," Rami Abdel Rahman, head of the UK-based Syrian Observatory for Human Rights, told the Associated Press news agency.
"Since the mission started the regime is limiting their movements and when they go out they are under the protection and supervision" of Syrian security forces, said activist Mustafa Osso.
Opposition groups say that on a visit to the main prison in the flashpoint city of Homs, the monitors were not initially given access to political prisoners being held there.
Human Rights Watch last week accused the Syrian authorities of hiding hundreds of detainees in military installations, which the observes do not have permission to access.
The Syrian regime has denied interfering with the operation of the mission.
State media Thursday reported that authorities had released 500 political prisoners in compliance with the Arab League peace plan.
Foreign Ministry spokesman Jihad al-Makdisi said the government was providing "protection and escort" for the monitors.
The head of the Arab League, Nabil al-Arabi, said on Monday the military has withdrawn heavy weapons from cities, although snipers were still in action.
In December, the monitors came under fire from protesters when they reported there wa "nothing frightening" to see in the flashpoint city of Homs.
The Arab Parliament on Sunday recommended the observers be withdrawn from Syria due to the ongoing violence.