(CBS News) LONDON - The civil war in Syria could be approaching a turning point. Rebels Saturday night are threatening the Damascus airport, the Assad regime's lifeline to its few remaining allies.
The outskirts of Damascus have become a battleground, with some of the fiercest fighting the city has seen yet. Syrian rebels say they're closing in on the capital, street by street.
Now within their sights is their biggest target: the Damascus International Airport, about 12 miles southeast of the city.
Heavy bombardment was reported Saturday in the suburbs in the surrounding area.
Rebel leaders called the airport a legitimate target, and gave a stark warning to the regime and outside travelers to avoid it at all costs.
Fighting near the airport road forced the suspension of commercial flights this week. Some airlines have already stopped altogether.
A rebel takeover of the airport would also cut off weapons supplies from regime allies like Iran, said Andrew Tabler of the Washington Institute for Near East Policy.
"It has the country's longest runways," he said. "It's from that location that jets from Iran land carrying a lot of sophisticated weapons. So knocking that location out, taking it over and holding it would allow the rebels to begin their push to Damascus without having the threat of resupply from the Iranians."
That makes it far too valuable for forces loyal to Syrian President Bashar al-Assad to give up without a fight.
The battle for Damascus and its airport might prove to be the bloodiest in more than 20 months of Syria's brutal civil war.