London Fire Brigade (LFB) said the women were conscious and breathing.

Photos on social media show the vehicle on the pavement having smashed into the front of the Poggen Pohl Kitchen Design Centre in Lavender Hill, causing the shop front to collapse.

The bus driver has been taken to hospital and other casualties are being treated at the scene, police said.

Andrew Matthews, 34, from Wandsworth, was one of about a dozen passengers on the bus.

"I was on the top floor at the back, fortunately," he said.

"I noticed the bus drifting. I heard a smash and saw the roof of the shop going through [the bus] from the front left. It went to the fourth or fifth row.

"I wedged myself in, bracing myself. As soon as the bus came to a stop there was yelling, screaming.

"I noticed a lady wedged in the front right-hand side. She was screaming for help. There was a lot of blood."

Another witness said smoke could be seen coming from underneath the bus.

Solange Morin, 33, who lives nearby, said: "I saw this woman shouting and banging on the glass. Everybody shouted 'fire, fire'.

"I went on to the bus. I talked to her and was holding her hands.

"She was pinned. I wouldn't have been able to get her out.

"She was so scared because people were shouting fire. There was a lot of smoke."

Another local resident, Brendan Pfahlert, said the crash "sounded like a large amount of glass being dropped".

London Ambulance Service said it had treated six people and remained on the scene. An air ambulance has also been sent.

In a statement, the ambulance service said it had sent five ambulance crews, two paramedics and an incident response officer to the scene at about 06:55 BST.

A Transport for London (TfL) spokeswoman confirmed the crash involved a route 77 double-decker bus and an investigation is under way.