The streets of Damascus are uncharacteristically empty on Saturday night, Zaina Shahla, a 42-year-old journalist living in the centre of the Syrian capital, tells the BBC.

After a “normal” morning, she said the streets were filled with people trying to stock up on supplies as reports emerged of rebel fighters heading for the city from both north and south.

Now, everyone seems to have gone home – the uncertainty of the situation creating a “sense of fear” among residents.

“We are afraid because we really don’t know what’s going to happen,” Ms Shahla said. “Nobody wants to see fighting in Damascus.”

She added: “Everything is ambiguous and nothing is clear for anyone.”

Her sentiments are echoed by Rim Turkmani, director of the Syria Conflict Research Programme at the London School of Economics.

Her sister in Damascus told her that shops are closing, supplies are running low and ATMs are out of cash, she said.

“No one knows what’s happening,” Ms Turkmani told the BBC.

Damascus has not seen the same degree of violence in Syria’s decade-long civil war, creating a sense of stability among some of its residents, Ms Shahla said. “If any change is going to happen, it won’t be easy.”

But reports suggest a turning tide is already sweeping through the city’s suburbs as rebel fighters led by opposition group Hayat Tahrir al-Sham (HTS) make sweeping territorial gains from the north of the country.

An unnamed US official told the BBC’s US partner, CBS News, that Damascus appears to be “falling suburb by suburb to the rebels”. The rebels themselves claim to have “encircled” the city.

Video footage appeared to show a statue of President Bashar al-Assad’s late father, Hafez al-Assad, being torn down by protesters in the southern suburb of Jaramana.

Syria’s state news agency claimed “sleeper cells” were publishing clips on social media from public areas of Damascus to suggest they had taken control of them “with the aim of spreading chaos among citizens”.

The Syrian government meanwhile denied rumours that Assad had fled the city.

Moreover, the interior minister has said there was a “very strong” military cordon around the capital.

But government forces have notably failed to provide any such defence in the cities, towns and villages that have fallen to rebel factions.

Rebel forces led by the Islamist group Hayat Tahrir al-Sham (HTS) have made a lightning advance over the past fortnight after launching a surprise offensive, capturing the north-western cities of Aleppo and Hama before continuing south and entering parts of the strategically important city of Homs.

Their progress has sparked an uprising by allied rebels in the southern region of Daraa, who have taken control of parts of the region.

The UN has said it is withdrawing “non-critical” staff from Syria amid the evolving situation. HTS has pledged to protect international organisations operating in the country.

The UN envoy to Syria has called for an orderly transition of power, as well as “urgent political talks” to implement a Security Council resolution that seeks a negotiated transition between the Syrian government and opposition.

Speaking in Doha on Saturday, Geir Pedersen said representatives of Iran, Russia, Turkey, the US, France, the UK, Germany and the EU had expressed their support for a diplomatic resolution.

Damascus’s residents have differing views about a rebel takeover, Ms Shahla said, but are bracing themselves for the possibility of armed conflict on their doorstep.

Her family have remained throughout Syria’s civil war, and have not considered fleeing – until now.

While they are not planning on leaving yet, she said, “if things escalate in a dramatic way or a dangerous way, maybe we will think about it”.

Additional reporting by Jake Lapham