A man who prompted an Armed Offenders Squad callout in West Auckland was shot after he threatened officers with a gun, police say.

Police were called to Mānutewhau Rd in Massey around 7.49pm on Wednesday amid reports the man had been in possession of a long-barrelled weapon.

He had allegedly also pointed the weapon at a neighbour.

A cordon was established around a property believed to be occupied by the man, at which time police say he fired at them.

"No police staff were struck or suffered any injuries," Waitematā District Commander Acting Superintendent Matt Laurenson said.

Police said negotiators tried to talk to the man, but that he didn't comply.

A series of tactical options were used to assist, including sponge rounds and Taser, but these had no effect on the man, and his behaviour has continued to escalate.

Police used a battering ram to enter the house about 10.45pm. An RNZ reporter at the scene said several loud bangs were heard, accompanied by bright flashes.

The man was subsequently shot by police.

The 55-year-old is in a serious but non life-threatening condition under police guard in hospital and will undergo surgery today.

"Having to use a firearm is the last thing any police officer wants to do, and in this instance our officers had no other option available," Laurenson said.

Charges have yet to be laid.