The main contingent of an Arab League observer mission has arrived in Syria to monitor an initiative to end the continued violence which has left thousands dead since anti-government protests began this year.
The head of the mission was reported to be heading to the city of Homs, where activists said security forces killed 30 people on Monday.
Under the Arab league plan, all armed forces must withdraw from areas of conflict.
Homs has been at the heart of a revolt against President Bashar al-Assad which began in March.
The government says it is fighting armed gangs. The BBC reports casualty figures are hard to verify as most foreign media are banned from reporting in Syria.
Syrian opposition activists, in a call backed by France, urged the observers to go to Homs immediately.
Syrian Foreign Ministry spokesperson Jihad Makdissi says the mission will be allowed to travel there if it chooses to.