Heavy fighting has continued unabated in Syria's second city Aleppo, as expectations grow that the army will launch a full-scale assault imminently.
A rebel commander on the ground told Reuters his fighters were preparing for a "strong offensive".
In Damascus, army sources said they had pushed rebels from a last stronghold. The rebels said they had withdrawn.
The fighting comes as 48 Iranian pilgrims were kidnapped from near a Shia shrine in the city on Saturday.
Iranian diplomats and Syrian state television blamed the abduction, which took place near the shrine of Sayyida Zainab in a suburb of Damascus, on "armed groups".
Fight for Aleppo
In the northern city of Aleppo, areas where rebels are entrenched have been bombarded by government forces and clashes have been reported in several districts.
President Bashar al-Assad's forces have reportedly used artillery, planes and a helicopter gunship to pound rebel positions.
Abdel Jabar Oqaida, a commander of the Free Syrian Army there, told the AFP news agency that the restive Salah al-Din district had "come under the heaviest bombardment since the battle began" on 20 July.
A senior government security official told the agency: "The battle for Aleppo has not yet begun, and what is happening now is just the appetiser... the main course will come later."
The fight for the key strategic city has been intensifying over the last few days, with Syrian state television reporting that troops had inflicted huge losses on what it called "terrorist mercenaries" in Salah al-Din and in other nearby areas.
Kim Sengupta of the UK's Independent newspaper told the BBC on Saturday from Aleppo that there are two front lines in the city, one in Salah al-Din and one near Aleppo's ancient iron gate.
There have been skirmishes in which rebels have done rather well, he said, seizing three police stations and retaking a fourth on Friday, and rebels are "incrementally" increasing the size of the area they hold.
However, he added that the full force of the government's military might has not yet been unleashed on the rebel strongholds.
'In government hands'
In the capital, government forces claimed to have pushed out rebel fighters from their final stronghold in the city, the southern neighbourhood of Tadamon.
An opposition activist told the AFP news agency from Beirut that the FSA had withdrawn from the district and would focus on "hit-and-run tactics against important regime targets".
On Saturday, shelling and gunfire were still heard in Tadamon despite it having been earlier stormed by government forces, the BBC's Jim Muir reports from Beirut.
State media has reported that the whole of Damascus is now in government hands, but such reports are impossible to verify and the situation on the ground is changing fast.
There has been no word yet on the fate of the Iranian pilgrims kidnapped in Damascus on Saturday, but the Syrian authorities said they were "working to handle the situation".
Thousands of Iranians travel each year to Syria to visit the pilgrimage site in the mostly Shia district of Sayyida Zainab, which has seen heavy fighting in recent weeks.
In May, 11 Lebanese Shia pilgrims were abducted in Syria while returning from Iran. The government announced three days after their capture that they had been released but there have since been conflicting reports in Lebanese media as to their whereabouts.
Activists say more than 20,000 people - mostly civilians - have died in 17 months of unrest.