"We have been in contact with UK holiday companies and there are about 100 clients in the Sichuan region at the moment," Abta spokesman Sean Tipton said.

He went on: "They are all safe and none are in danger. In line with Foreign Office advice, there will be no tours to that region for the time being."

The Foreign Office has advised against all but essential travel to Sichuan province, where Monday's earthquake has killed at least 12,000 people.

While Abta was able to account for those Britons on organised tours, it has still not been established if any other travellers from the UK are in the area.

A Foreign Office spokeswoman said: "We have no confirmed reports of any Britons being hurt in the earthquake. We are working on trying to track down all the Britons in the area."

The Foreign Office has been unable to confirm a report from China's Xinhua News Agency that a group of 15 British tourists "were out of reach on Tuesday morning in Wenchuan", the epicentre of the earthquake.

The quake had a magnitude of 7.9 on the Richter Scale, making it the country's worst for 30 years, with most of the casualties in Sichuan province.

The Foreign Office has now set up a telephone number for people to contact if they think their loved ones may have been involved in the disaster - 0086 105 192 4499.

Mr Tipton said one of the main reasons for people visiting the earthquake-hit region was to see giant pandas. He went on: "There are people due to go out there in the next few days and obviously they will not be travelling there now."