The incident happened in Parry Place near the A206 and Woolwich Station just before 1.30pm today (March 27).
Emergency services attended and a man was rushed to hospital where his condition was initially unknown.
A spokesperson for Metropolitan Police has now confirmed he remains in hospital in a critical condition.
No arrests have been made as police enquiries continue.
A crime scene remains in place at the junction of Spray Street and Parry Place, home to restaurants and a church.
Local shop owner Chinyere Iwunna said: “It’s a very big shock to everybody. We have not had something like this for a long time.
“There are lots of police. They closed the road and asked us to go.”
She said the police came into her shop and told her she would have to close due to the incident on the street outside.
A spokesperson for Metropolitan Police said: “Anyone with information is asked to call police on 101 quoting CAD 3693/27MAR.”
