Syrian troops have launched fresh assaults on rebels as the government prepares to host an envoy of UN mediator Kofi Annan.
The Syrian Observatory for Human Rights says several towns have been shelled including Homs, Deraa and Damascus.
The envoy Robert Mood is scheduled to discuss the deployment of ceasefire monitors across Syria.
The delegation in Syria hopes to agree with the Syrian government how a mission of 250 unarmed observers will be structured and how it will operate.
Meanwhile, activists say dozens of people have been killed in recent clashes.
The human rights group Amnesty International said it had counted 232 deaths since Syria accepted Annan's six-point peace plan last week.