British tourists have been warned to avoid all but essential travel to Thailand after the worst violence seen in Bangkok for 16 years left one person dead and more than 40 injured.

British tourists have been warned to avoid all but essential travel to Thailand after the worst violence seen in Bangkok for 16 years left one person dead and more than 40 injured.

The Foreign Office reissued advice to travellers to avoid the capital following more violent clashes between police and anti-government protesters.

It also warned that Britons undertaking travel to, or through, the far southern provinces of Pattani, Yala, Narathiwat and Songkhla must exercise "extreme caution"and only those who absolutely have to should journey through the areas.

Several other countries, including Australia and New Zealand, advised people to "exercise a high degree of caution", while Canada and the US urged travellers to avoid demonstrations in Bangkok.

The Duke of York postponed a three-day visit to Thailand after Prime Minister Samak Sundaravej declared a state of emergency in Bangkok.

Instead of visiting Thailand, Vietnam and Singapore over six days next week as the UK's Special Representative for International Trade and Investment, the duke will now travel only to Vietnam and Singapore.

The duke's office said yesterday: "With the agreement of the Royal Thai and British Governments, the Duke of York has decided it would be appropriate to postpone his official visit to Thailand to a later date."

Trouble began last week when anti-government protest group the People's Alliance for Democracy occupied state buildings in Bangkok, demanding the resignation of Mr Samak.

About 500 of his supporters marched through Bangkok, vowing to retake Government House.

Gangs armed with sticks, knives, slingshots and other makeshift weapons chased each other through the streets.

One person, identified as a 55-year-old man, died from severe head injuries and nine others were taken to hospital, at least three with gunshot wounds. Another 33 people were treated for injuries and sent home.

Mr Sundaravej called the emergency decree the "softest means available" for restoring order. It gives the military the right to restore order and authorities the right to suspend civil liberties, ban public gatherings of more than five people and restrict reporting.

Foreign Office Minister Meg Munn said she was following developments in Thailand with "deep concern".