A witness in a jury trial of four Tauranga people accused of a raft of assault charges has described how he fired a shotgun into the air to stop the armed group heading for the front door of a family home.

Kevin Duncan told the jury of 12 he had taken the shotgun from the gun safe as people armed with sticks, bats and garden tools, struck down his father outside his Te Puna home late on November 23, 2012.

He loaded the shotgun and pointed it overhead near the top of the steps, so he could get out from under the porch roof.

They stopped moving forward when he fired the first shot, but they were reluctant to move back.

'I reloaded and they started very slowly to back down,” the Te Puna man told the jury in Tauranga District Court yesterday.

He had fired three warning shots, and by that point reached the bushes where his father Andrew Duncan had gone down under several attackers. Andrew had been pulled out from the bushes and was able to stand, though he was covered in blood from head wounds.

'He said he was okay, so I handed him the shotgun and ran back into the house for more ammunition.”

He soon returned and took the weapon back as his father was suffering the effects of the beating, and there were still a large number of people on the Te Puna Road property.

He cleared them out moving down the drive firing more shots into the air, and saw the remainder leave in the vehicles they arrived in just a few minutes earlier.

He fired a total of seven warning shots into the air during the incident Crown prosecutor Greg Hollister Jones told the court was a 'short campaign of violence”.

On trial is Jack Simon Ake, 52, Rihari Jarrod Borell, 28, Jasmine Hira Borrell, 25, and Derek Michael Drewery, 27.

Ake is charged with injuring with intent to cause grievous bodily harm and wounding with intent to cause grievous bodily harm.

Jasmine Borrell is facing one count each of wounding with intent to cause grievous bodily harm, injuring with intent to cause grievous bodily harm, assault with intent to injure, assault with a weapon, common assault and possession with an offensive weapon.

Rihari Borrell is charged with two counts of injuring with intent to cause grievous bodily harm and two counts of assault with a weapon.

Drewery is facing one count each of injuring with intent to cause grievous bodily harm, wounding with intent to cause grievous bodily harm and common assault.

They are accused of first turning up at the Duncan house about 11pm on November 23 and assaulting the young people who were gathered near the shed.

They left promising to return, and they did 15 minutes later with another carload of young men allegedly armed with sticks, garden tools and pieces of pipe.

They are alleged to have swarmed the property, smashing vehicle windows and assaulting people they encountered.

The jury trial before Judge Christopher Harding is proceeding.