Thousands of people have fled to Kabul to escape street fighting and are living in makeshift camps
The Taliban have captured Afghanistan’s second largest city, Kandahar, in what is a crushing blow for the government and a major win for the militants.
The southern city was once the Taliban’s stronghold, and is strategically important as a trade hub.
The insurgents also seized the nearby city of Lashkar Gah and now control about a third of Afghanistan’s provincial capitals.
Tens of thousands of civilians have fled the Taliban advance.
Many have travelled to the capital Kabul to seek safety and are sleeping on the streets there.
“We have no money to buy bread, or get some medicine for my child,” a 35-year-old street vendor who fled northern Kunduz province after the Taliban set fire to his home told the BBC.
More than 1,000 civilians have been killed in Afghanistan in the past month, according to the UN.
The insurgent advance comes as US and other foreign troops withdraw after 20 years of military operations.
The US is to send nearly 3,000 troops to Kabul airport to evacuate a “significant” number of embassy staff on special flights. The UK is deploying 600 troops to support British nationals leaving the country. Staff at the British embassy have been reduced to a core team.
‘From here where else do we run?’
By BBC’s Yogita Limaye in Kabul
People are in disbelief about what’s happened in a single day. Five provincial capitals – among them major cities – fell to the Taliban on Thursday.
In Kabul, thousands of people have been arriving – but this is a number that changes by the hours. They’ve left with very few belongings. These are people, who had homes and jobs, and shops and farms – and they just had to leave everything behind and try to run to safety.
Some of them have taken days, and these are dangerous journeys – past Taliban checkpoints and active frontlines – to get to Kabul. This is the last place many of them believe they can go to. They say, from here where else do we run?
They are angry at the government about being left to fend for themselves. The government says it is going to house them in mosques and provide them with the relief – but there is not enough for everyone who is coming in.
There’s anger too that the US and UK are evacuating their own citizens and leaving Afghans to their fate.
Why is Kandahar so important?
Kandahar is the Taliban’s birthplace, and so taking control of the city of 600,000 people is a significant prize for the militants.
They had occupied the city’s outskirts for a number of weeks before launching their attack on the centre.
On Wednesday, the Taliban breached Kandahar’s central prison, and on Thursday, images on social media reportedly showed insurgents in the city centre.
A resident told the AFP news agency that government forces appeared to have withdrawn en masse to a military facility outside Kandahar.
Kandahar is considered strategically important because of its international airport, its agricultural and industrial output and its position as one of the country’s main trading hubs.
Ghazni, captured on Thursday, is also a significant gain for the Taliban as it is on the Kabul-Kandahar motorway, linking militant strongholds in the south to Kabul.
Meanwhile Herat, an ancient silk road city, had been under siege for weeks before security forces on Thursday retreated to army barracks. Video on social media shows the insurgents running through a central street firing their weapons, and the Taliban flag was seen flying over the police headquarters.
And Lashkar Gah is of symbolic value to the insurgents as Helmand was the centrepiece of the US and British military campaign in Afghanistan.
The US embassy in Kabul said it was hearing reports that the Taliban were executing Afghan troops who were surrendering, saying it was “deeply disturbing and could constitute war crimes”.
An estimated 72,000 children are among those fleeing to the capital in recent days and are mostly sleeping on the streets, according to Save the Children.
Makeshift camps have been established on scrubland on the outskirts of the capital, while many others have reportedly been sleeping on the streets or in abandoned warehouses.
In response to the insurgency, the German government has threatened to end its annual financial support of $500m (£360m) to Afghanistan if the Taliban gains complete control of the country.
Germany has also suspended the forced repatriation of Afghan citizens whose asylum applications have failed. The French and Danish governments say they will also following the same policy.