A man has been airlfited to Addenbrooke's Hospital in Cambridge with critical injuries following a police incident in Peterborough today.
Police, ambulance crews and the air ambulance were called to a concern for safety of a man in Celta Road, Peterborough, at 8.40am.
A man was taken to Peterborough City Hospital. with serious, life threatening injuries, but has since been airlifted to Addenbrooke's.
The road is shut at the junction of Hotpoint with Belsize Avenue.
Police tweeted to say: "Please avoid the area while emergency services deal with a serious incident."
A police spokeswoman added that the road is likely to be closed for some time.
UPDATE: The road was reopened at around 2.30pm.