Police shot dead a bull that went on the run forcing the closure of a dual carriageway and the evacuation of a playing field.
Hertfordshire Police said a firearms officer shot the bull after it escaped from a field and ran onto Martins Way in Stevenage.
The road was closed but the bull ran on to a nearby playing field, forcing police to seal off all the exits.
Officers then secured the permission of the owner to kill the animal.
No-one was injured but a police spokeswoman said the decision to shoot it was made "because of fears over public safety".
Supt Nat Briant said: "These were very extreme circumstances and there were concerns that members of the public could have been in danger.
"Sadly, the animal was so distressed and agitated that, with the acceptance of the owner, we had to put it down in order to protect the public."