Image copyright Getty Images Image caption Track Palin (left), an Iraq war veteran, appeared regularly with Mrs Palin at campaign events

The son of former Republican vice presidential nominee Sarah Palin has been charged with assault and burglary after a confrontation with his father involving a firearm.

Police say Track Palin allegedly broke into his parents' Alaska home through a window on Saturday night.

Documents obtained by US media say the 28-year-old said he was on pain medication and had been drinking.

He was arrested in 2016 for allegedly punching his girlfriend.

After he eventually pleaded guilty to possession of a firearm while intoxicated, other charges were dismissed in that case.

Police documents, published by the LA Times newspaper, said Mrs Palin called the police at about 20:40 on Saturday night (06:40 GMT on Sunday) to say her son was on "some type of medication" and was allegedly "freaking out".

The affidavit by a responding officer said they found the former Alaskan governor "visibly upset" at the property.

Image copyright Getty Images Image caption Mrs Palin has said previously that her son has suffered from Post-Traumatic Stress Disorder

Police say that when they arrived they had a stand-off with Mr Palin in which he moved around the house and at one stage went out onto the garage roof. They say he demanded police put their weapons on the ground and allegedly called them "peasants".

Police say the struggle between the two men happened after Mr Palin said he was coming to the property to retrieve a vehicle, and threatened to beat his father.

Todd Palin, Mrs Palin's husband, told police he armed himself with a pistol when his son arrived, but was disarmed and was left bloodied.

Track Palin was charged by police with first-degree burglary, fourth-degree assault and criminal mischief, and remains in police custody.

A statement to US media from the family requested privacy, and said the Palins were unable to comment further on the case.

Earlier this year his ex-girlfriend Jordan Loewe applied for a protective order against Mr Palin, having previously requested full custody of their one-year-old son.