The victims were among 18 people on board a coach travelling to Medina as part of an Umra pilgrimage to Mecca.
The Foreign and Commonwealth Office confirmed Britons were among a number of victims in the crash, which happened in a town roughly 30m (48km) north of the holy site of Mecca.
The driver of the petrol tanker is also believed to have died, reports The Independent.
Four UK travellers have been killed, and a further 12 injured, in a coach crash in Saudi Arabia, according to travel company Hashim Travel.
"My thoughts are with the family and friends of those that are reported to have been invlolved in an accident in Saudi Arabia", he tweeted.
The Saudi Arabian Embassy in London said the accident involved the bus the passengers who died were riding in, a small vehicle and a gasoline tanker truck.
2 infant girls left in suitcase on curb by MI mother
Police say a 26-year-old MI mother left her two infant daughters inside a suitcase next to garbage on the side of the road. Officers returned to the woman's house and discovered that two of her young children were nowhere to be found.
Britain's Foreign Office called the collision near the town of Al Khalas in west Saudi Arabia a "serious road traffic accident".
The Umrah pilgrimage is optional for muslims and on a smaller scale than the annual Hajj pilgrimage, which muslims are obliged to undertake.
Mr Zaman said the company has been running specialist Hajj and Umrah tour packages for 15 years.
Those killed were from Blackburn and Preston, in Lancashire, travelling from Mecca on an Umrah pilgrimage with Blackburn-based Hashim Travel, the BBC reported.
A spokesperson for CBHUK (The Council of British Hajjis) a national pilgrim welfare charity said "Our thoughts and prayers are with the families of those who have been affected by this tragic accident whilst on the Umrah pilgrimage to the holy lands. My prayers and thoughts for them and their family at this hard time".