Arabella Restaurant and Bar has been a popular institution on King Street for the past 14 years, but on Tuesday it looked more like the scene of a war zone.

At roughly 1am, the windows that lined the 12-metre restaurant front appear to have been repeatedly bashed with a hammer.

"At first I thought it was a shooting. I was really scared. I had only left [the restaurant] about 20 minutes earlier," said Arabella owner and chef Mohamed Zouhour after seeing the damage.

Police were contacted by a witness who said he saw a man breaking windows at a restaurant on King Street about that time.

The witness made a U-turn, but by the time he passed Arabella again, the man was gone.

The offender was described as aged in his 30s or 40s, with very short hair or bald. He was wearing a grey jumper and grey tracksuit pants, the witness told police.

The perpetrator did not appear to have stolen anything, but the damage has cost the restaurant's owners more than money, Mr Zouhour said.

It is not clear whether the incident was racially motivated.

But Mr Zouhour and his family were afraid to go to work and were contemplating leaving the area after enduring six months of racial abuse in the form of harassing phone calls and crude vandalism, he said.

On Saturday morning, Mr Zouhour arrived at work to find the words "F--- Arabs" etched into one of the restaurant's window panes.

The incident was not reported to police.

The same message had been scrawled on the restaurant's back door weeks earlier.

Last week Mr Zouhour answered an anonymous call only to be bombarded with racial slurs.

"They called me a 'bloody Lebanese', they told me 'Move out of the area, you can't be in Newtown, get out,' " Mr Zouhour said.

His staff have taken similarly abusive calls on the restaurant's landline over the past six months, he said.

"I loved it here, and the locals are great, but this is too much. It's scary, I'm scared," he said.

"I find myself thinking I should take my family and go. I don't feel protected in this country," he said.

Mr Zouhour posted two photographs of the smashed windows accompanied by an impassioned message on his Facebook page.

"Talking about racist people this what happen at my restaurant ... and they left racist comments on the glass," the post read.

Mr Zouhour declined to give a statement when police arrived at 2.30am, but did so later on Tuesday after police made further inquiries.

The restaurateur was not sure why his restaurant has been targeted in recent months, but he said he has seen more intolerance of Arabs in connection with global upheaval associated with Islamic State.

"Maybe some people think that anyone whose name is Mohamed is part of all that," he said.

"They think because my restaurant is so successful that I'm the leader of the Arabs, but I'm nothing. I consider myself Australian," Mr Zouhour said.

"I've been here all my life," he said.

The restaurateur has been forced to close Arabella and cancel several events that were scheduled over the next few days while he waited for the glass front to be repaired, which could cost up to $15,000.

Police were investigating Tuesday morning's vandalism and the racist comment on the window pane.

They urged people with information about the attacks to contact Crime Stoppers on 1800 333 000.