The bus driver in charge of a coach that crashed, killing 10 people and injuring another 25 has been arrested and police expect to lay charges.

The coach carrying wedding guests back to their accommodation rolled in the Hunter Valley town of Greta, north of Sydney, at 11.30pm on Sunday night.

Police said 25 people were injured in the accident and were taken to area hospitals by helicopter and by road. A further 18 passengers were uninjured in the accident in New South Wales.

The driver of the bus, a 58-year-old man, has been arrested and will be charged, Police Assistant Commissioner Tracy Chapman said.

A roadblock is set up near the town of Greta following a bus crash in the Hunter Valley, north of Sydney. Photo / AP

She would not detail the allegations, but she told reporters “there is sufficient information ... for us to establish that there will be charges.” She would not comment on whether speed was a factor.

If the driver was hurt, his injuries were minor and he was a nearby Cessnock police station on Monday, Chapman said.

Police inspect underneath a bus that rolled onto its side near in the Hunter Valley. Photo / AP

The accident happened just after 11:30pm in foggy conditions at a roundabout on Wine Country Drive in the town of Greta. Police said they had established a crime scene at the site and had started an investigation into the cause of the crash.

A bus crash near Greta, NSW, has left 10 people dead and multiple injured.

The guests had earlier attended a wedding at the Wandin Estate Winery and were heading for their accommodation in the Hunter Valley town of Singleton, Chapman said. One guest told Seven News it had been a nice day and a fairytale wedding.

Australian Prime Minister Anthony Albanese tweeted a thanks to first responders.

“All Australians waking up to tragic news from the Hunter send our deepest sympathies to the loved ones of those killed in this horrific bus tragedy,” Albanese wrote. “For a day of joy to end in such devastating loss is cruel indeed. Our thoughts are also with those who have been injured.”

Jay Suvaal, the mayor of Cessnock, said the crash was “truly horrific.”

“We are a major wedding and tourist destination in the Hunter Valley, and so there will be people from all over the state and the country that have been to these areas and have probably done similar things,” he said. “I think it will send shock waves right through the broader community.”

Assistant Commissioner Tracey Chapman addresses the media in Huntlee near the scene of a bus crash in the Hunter Valley, north of Sydney which left 10 people dead. Photo / AP

Greta is in the heart of the Hunter Valley wine region, a picturesque area dotted with vineyards and restaurants. It was the first wine region established in Australia.

Specialist crash investigation and forensic units are now at the scene and police warn that road closures “will be protracted”.

- with AP