Edinburgh's famous Hogmanay celebrations are being overhauled after a new company took over running the event.

A six-hour street party carnival is at the heart of the "revamped" programme by entertainment company Underbelly.

Bosses vowed the city's new year celebrations will be "refreshed, re-energised and better than ever before".

Under the festival's 25th birthday programme, the 60,000-capacity street party will begin at 7pm and last until 1am on New Year's Day.

Bands and DJs on stages, street performers, dancers, acrobats, flash mobs and fire eaters will all combine to bring a carnival-type spirit to Princes Street.

Actor and presenter Sanjeev Kohli, best-known for playing shopkeeper Navid in the BBC comedy Still Game, will host the street party, helping to entertain the crowds and guide them through the arena.

An extended fireworks display from the ramparts of Edinburgh Castle will see in the new year when the midnight hour strikes.

The three-day festival opens on December 30 with the traditional Torchlight Procession.

It will blaze a new path through the historic heart of the city this year, around Holyrood Palace and the Scottish Parliament towards Holyrood Park.

The event will also mark the beginning of 2018 as Scotland's Year of Young People, organisers said.

The following day, families will have the chance to celebrate new year together in West Princes Street Gardens at a new event entitled Bairns Afore.

The family-friendly celebration includes an hour of entertainment and ends with its very own "midnight" fireworks moment at 6pm, enabling families to take their children home before the late night fun gets under way.

On New Year's Day, people will get the chance to take part in the annual dive into the chilly Firth of Forth for the Loony Dook in South Queensferry, raising money for a range of charities in the process.

At dusk, the Unesco city of literature will celebrate its literary heritage with projections across buildings and landmarks around the city.

Underbelly took over the contract from Unique Events earlier this year.

Directors Charlie Wood and Ed Bartlam said: "We are humbled and thrilled to be delivering a new programme for Edinburgh's Hogmanay in 2018.

"Edinburgh can claim to be the home of new year festivals and we will work hard to ensure the programme delivers something fresh and exciting every year to keep residents, UK visitors and international tourists flocking to this world famous festival city through the winter months."

Winter festivals minister Alasdair Allan said: "Hogmanay hugely contributes to promoting Scotland as a fantastic visitor destination, a host of the world's major events and a dynamic country rich in culture and creativity.

"Most importantly, it enhances Scotland's reputation as a place where everyone is assured a warm welcome, whether they are visiting the country, are here for business or to study, or have chosen to live and work here."

Edinburgh City Council awarded the three-year contract for the Christmas and Hogmanay festivities to Underbelly earlier this year.

Tickets for a number of the events are on sale from Tuesday.