Fierce fighting splits up Syrian capital Syrian forces shelled areas fringing Damascus on Thursday and mounted tight security in the city centre, as part of an expanding campaign that echoes efforts in other cities to preserve the regime's dwindling zones of control. Loyalist troops who once drove lightly-armed rebels out of suburban bolt-holes in the capital with relative ease are now mounting an aggressive rearguard action against fighters who have spread to more districts, stormed military bases and captured government weapons. The rising violence is part of a pattern of regime bombardments and effective partitioning in other cities, such as Aleppo and Homs, during the near 21-month uprising against President Bashar al-Assad's regime. Independent analysts say the regime has moved tens of thousands of troops to Damascus as the number of rebel fighters has grown in what is becoming a ferocious showdown. Analysts say a long-expected opposition push into Damascus is likely to be met by strong resistance from regime forces, resulting in another drawn-out confrontation that will be all the more ruinous because it is in the capital. "The opposition can't bet on the regime crumbling," said Peter Harling, a Syria analyst at the International Crisis Group. There's a risk it won't - there may be fighting neighbourhood by neighbourhood. How do you manage transition if you destroy the seat of power? Regime guns boomed out repeatedly in Damascus around dusk on Thursday, witnesses said, the latest salvo in a week-long campaign against rebels who have taken new territory around the city, over-run at least two military bases and caused airlines to suspend flights because of fighting near the airport road. Damascenes say there are more regime security posts than ever before around the city, with frequent pounding of suburban areas by artillery and aircraft. "Checkpoints are everywhere, the sounds of bombing are heard everywhere and you can see columns of smoke almost wherever you look," said Osama, an activist in the capital. I think these battles will reach Damascus centre soon. While regime supporters still express confidence in victory - Omran al-Zoubi, information minister, told the BBC on Wednesday that the army would win the battle for Damascus in a few days - some now betray signs of anxiety and fatigue. "Everyone is very tired," said a pro-Assad teacher who lives in a south Damascus district where loyalist and Free Syrian Army forces have clashed in the past. We don't know where and when we will stop fighting. Yet - for all the undoubted gains by opposition forces around the capital - it is by no means clear that they are on the verge of decisive breakthrough. Just as the third city of Homs has remained divided amid massive destruction since the revolt started, the broad contours of the fighting in Damascus are not so different from a year ago, with rebels operating mainly from a set of suburban strongholds concentrated in the city's northeast, south and northwest. The airport road to the southeast has been the site of fierce fighting partly because of the geographical accident that it runs between two strongly pro-opposition areas. Opposition supporters are also aware that previous incursions into central Damascus have foundered, just as the rebels failed to achieve the victory they predicted in Aleppo while advancing there in numbers in July. When rebel fighters launched an offensive in the heart of the capital during the same month, sending fighters to areas such as Midan, they were ejected from most districts by regime forces in little more than a week Amr al Azm, an opposition-affiliated academic at Shawnee State University in the US, said the government is showing signs of entrenching itself militarily in Damascus - as it has done in other large urban centres surrounded by rebel-held countryside. "From a tactical perspective, already you're beginning to see stalemate," he said. Few observers foresee a Libya-style quick rebel march into the centre of the capital. Analysts think the pattern is far more likely to resemble the battle for the biggest city of Aleppo, where rebels have been in a destructive deadlock with regime forces for more than four months since making their move - alienating some citizens in the process, including natural opposition supporters. "This is civil war, where everyone is considering himself a winner," lamented one anti-government activist in Damascus. So we will have quite a time when people are killed and killed and killed.