Two people have reportedly been shot in Woolwich, south east London, after armed police were called to a machete attack, eyewitnesses say.
Dozens of weapons and pools of blood could be seen on the ground in John Wilson Street, where a man wearing a Help for Heroes T-shirt is said to have been attacked.
Police were sent to the scene at around 2.20pm.
The immediate area has been shut down, with eyewitnesses describing the incident on Twitter as "horrific".
On its Twitter account, the Metropolitan Police helicopter team called the incident "serious".
A Scotland Yard spokesman said: "We believe at this stage officers were called to reports of an assault."
London Air Ambulance confirmed one patient was airlifted from the scene, while another was taken away by road ambulance.
The service would not confirm the nature of their injuries or where they were being taken.
