Suicide bombers killed at least 50 people at checkpoints in Hama and Jaramana, a suburb of Damascus inhabited mainly by Christians and Druze, and fighting flared around the capital and in the eastern province of Deir al-Zor.
The UK-based Syrian Observatory for Human Rights said the al-Qaeda-linked al-Nusra Front carried out the attack.
Meanwhile, the release of 126 women held in Syrian jails could not be confirmed yesterday as the families of nine Lebanese Shia pilgrims and two Turkish airline pilots celebrated their liberation in a three-way exchange deal brokered by Turkey and Qatar.
The Lebanese and Turkish hostages flew home in private Qatari jets and were greeted by politicians and relatives on arrival.
The rebel Northern Storm Brigades, who held the pilgrims for 17 months, claimed the women had been freed and were on their way from Damascus to Turkey. Lebanese officials have thanked Damascus for agreeing to free scores of the 500-700 women detained in Syria, the principal demand of the brigades. Activists could not confirm their release.
The Turkish pilots, Murat Akpinar and Murat Agca, were abducted in August by a group demanding that Ankara use leverage with the rebels to release the Lebanese abducted who were abducted while returning home after visiting Shia shrines in Iran. Turkey has close ties with the hostage-holders, who are affiliated with the western- and Arab-backed Free Syrian Army.
UN humanitarian agency head Valerie Amos called for a ceasefire in three suburbs of Damascus to permit the delivery of food supplies to starving civilians. The situation is so desperate that clerics have issued a religious ruling permitting the consumption of dogs, cats and donkeys.
Following consultations with UN envoy Lakhdar Brahimi, Arab League chief Nabil al-Arabi announced that the international conference aimed at ending the Syrian conflict is to meet in Geneva on November 23rd-24th.
However, Mr Brahimi warned that the meeting could not take place without a “credible opposition, representing an important segment of the Syrian people”. He is due in Damascus and Tehran to discuss the conference.