Dash cam footage has captured the horrifying moment two men smashed up a man’s car with hammers – while he was sitting inside it.

Hackney Gazette: David Grunfeld's smashed windscreen. Picture: David GrunfeldDavid Grunfeld's smashed windscreen. Picture: David Grunfeld (Image: Archant)

Terrified David Grunfeld, 24, feared the suspected thieves might even use the weapons to “smash his head”.

But after delivering 10 brutal blows to the windscreen, they jumped back in their Ford van and sped off.

Mr Grunfeld was pursuing them, believing they had stolen his top-of-the-range sound equipment. He delivers audio kit for his family firm DG Sound and had parked his van in Fairholt Road, Stoke Newington, on March 10.

When he returned in a car half an hour later he saw two men unloading the equipment.

Hackney Gazette: This man may have information about the attack and theft. Picture: David GrunfeldThis man may have information about the attack and theft. Picture: David Grunfeld (Image: Archant)

He tried to block them with the vehicle – but the men spotted him and hared off in their own van.

Mr Grunfeld, who had already had £10,000 worth of equipment stolen on February 1, decided to chase them. He called 999 immediately and filmed his pursuit on the dash cam.

“It was dangerous,” he said. “They were going the wrong way up roads, in between cars and through red lights. They did not care that cars were coming and people were crossing the roads. They drove like crazy – at 60mph, at least.

“I was talking to the police the whole time on the phone giving them updates with the situation.”

Hackney Gazette: A man smashes David Grunfeld's windscreen. Picture: David GrunfeldA man smashes David Grunfeld's windscreen. Picture: David Grunfeld (Image: Archant)

But when a car ahead blocked their journey in Vartry Road, the two men suddenly jumped out of the van and ran towards him.

“They came out with two hammers,” said Mr Grunfeld. “They started to smash my window. It was horrible. I thought they were going to smash me once the window was smashed and that they would knock me on my head.

“They started smashing my windscreen so I wouldn’t be able to see them any more or be able to chase them – and there is where it ended.

“It was really, really scary, the whole chase, from one second to the next.”

The thieves made off with an estimated £10,000 worth of sound systems, speakers, keyboards and mics.

Anyone with information is asked to call police on 101.