An army statement reported by state TV said the army reserved the right to respond decisively “using all forms of fire to any violation by the armed groups”.
The Syrian Observatory for Human Rights said major conflict zones in Syria were calm after a ceasefire took effect.
“Calm is prevailing,” Observatory Director Rami Abdulrahman told Reuters, giving an early assessment of the impact of the agreement brokered by the United States and Russia.
He said there had however been some shelling by both rebel and government forces in the southwest of the country.
The Observatory gathers its information from a network of sources in Syria.
