Runway cow shot dead on busy NZ street

New Zealand police have come under fire for their "Rambo tactics" after the shooting death of an escaped cow by an officer on a busy street.

The cow was spotted running down Puriri Street in the North Island town of Whanganui on Monday morning.

After charging at a man in a mobility scooter and police officers "several times", police said they were forced to take drastic action.

In footage captured on a bystander's dashcam, a police car drives ahead of the cow, before an officer jumps out and shoots the animal once in the head at point blank range.

"That motherf----r let a round off down the road!" the man in the car behind says.

"That bullet could have come at us."

Police said an officer later fired "several more shots" at close range, killing the cow.

"This incident happened at a busy time in full view of the public and we appreciate this must have been a traumatic event to have witnessed," said Senior Sergeant Paul Baskett of Whanagnui police.

"Our staff acted based on their immediate safety concerns at the time. This was a big animal and had they not acted there was a real risk that it could have caused serious injury."

But users on social media have slammed the police's heavy-handed response.

"The argument isn't over whether the cow was a risk to anyone but more the excessive and unnecessary use of a firearm in a residential street," a user wrote on Facebook page NZ Farming.

"As its only a 50kph zone there are plenty of safer options than going full Rambo in a residential street at school time."

It is not currently known where the cow had escaped from.