UN-Arab League envoy Lakhdar Brahimi waded back into the Syrian fray on Thursday, even as opposition and regime troops fought pitched battles for control of key northern towns leaving dozens dead.
Brahimi's arrival in Saudi Arabia for talks with officials in the kingdom comes amid rising tension between Syria and Turkey, made worse after a Syrian passenger jet was forced to land in Ankara where some of its cargo was seized.
The envoy, who has previously held out little prospect for a negotiated end to a conflict both sides seem determined to decide on the battlefield, would have "wide-ranging talks on the prolonged crisis in Syria," said his spokesman.
Brahimi had first gone to the Middle East in mid-September, visiting Damascus, where he met Syrian President Bashar al-Assad -- but earned no promises of concessions from him.
In an interview with AFP on Tuesday, UN Secretary General Ban Ki-moon said Brahimi would soon return to Damascus to try again to meet with Assad.
Ban suggested Brahimi could go to the Syrian capital next week if his meetings in the region this week were productive.
Brahimi's second regional tour comes as Syrian forces battle opposition across the country, with fighting focused in an eastern belt of Damascus, in the northern city of Aleppo, in the central city of Homs and in Daraa province in the south.
The Syrian Observatory for Human Rights said at least 69 people were killed in clashes Wednesday in the northern province of Idlib, where opposition are trying to secure a swathe of territory abutting the Turkish border that will serve as a "buffer zone."
Regime forces from early Thursday resumed shelling of Maaret al-Numan, seized two days earlier by opposition and which has since been the theatre of heavy fighting, the Britain-based watchdog said.
Syria's army has sent reinforcements to help retake Maaret al-Numan and other nearby towns so that road links can be restored with Aleppo, which since mid-July has been one of the main focuses of the civil war.
But insurgents say they have been trying to halt the advance using rocket launchers and improvised explosive devices.
The opposition on Wednesday launched an attack on army positions in Aleppo's landmark Umayyad Mosque in the heart of the Old City adding to the urgency for the army to restore its supply lines.
In the central province of Homs, the town of Qusayr and rebel districts in the city of Homs were shelled and bombed by warplanes on Thursday, the Observatory said.
The army has intensified operations against Homs and Qusayr, which have been besieged by troops for months, vowing to overrun them by the end of the week to free up forces for northern battle zones.
Nationwide at least 198 people were killed across Syria on Wednesday, the Observatory said, adding to more than 32,000 who have died since the start of the uprising in March 2011.
Assad's regime has insisted the insurgents must stop the violence first as it turned down a call issued by the UN secretary general.
"We told Ban Ki-moon to send emissaries to the countries which have influence on the armed groups, so that they put an end to the violence," foreign ministry spokesman Jihad Maqdisi said on Wednesday.