Damascus and its suburbs were bombarded Tuesday, and air force jets hit the nearby cities of Sahm and Aqarba in an attempt to push rebel fighters further from the capital. On the ground, military forces attacked rebel strongholds on the road to Damascus airport.

The attacks create doubts about diplomatic efforts to end the 21-month conflict.

Rebel forces have been fighting for weeks to take control of Damascus. Analysts say the army is set on taking total control of the city and its immediate surroundings to create conditions necessary for future dialogue.

In northern Syria, where insurgents control large amounts of territory, the government announced the closure of Aleppo airport due to rebel attacks in recent days.

"There have been continued attempts by opposition militants to target civilian aircraft, which could cause a humanitarian disaster," an airport official told the AFP news agency.

Diplomatic efforts

Syrian Prime minister Wael al-Halaqi said Monday the government was open to talks to end the conflict, which has claimed some 46,000 lives thus far.

"The government is working to support the national reconciliation project and will respond to any regional or international initiative that would solve the current crisis through a dialogue and peaceful means and prevent foreign intervention in Syria's internal affairs," al-Halaqi told parliament.

The United Nations' Arab League envoy, Lakhdar Brahimi, crafted a ceasefire proposal that he said Sunday "could be adopted by the international community."

His plan is based on an agreement reached by world powers in Geneva in June that calls for the formation of a new government and election plans, but al-Halaqi said the conflict must be resolved only by the Syrian people.

The opposition already rejected the agreement reached in Geneva, and has said President Bashar Assad must leave before any negotiations can take place.

Many diplomats and analysts predicted Assad would go in 2012, but he remains in power. His government still largely controls the military, and rebel fighters have struggled to hold major cities, saying they are defenseless against his air force.

dr/jm (AFP, Reuters, dpa)