POLICE in Thailand are widening their investigations into a series of bomb attacks on Tesco stores that threaten to undermine the store group's Far East strategy. The latest attack happened 10 days ago when a device exploded in the car park of a Tesco hypermarket in Ubon Ratchathani, but no-one was hurt.


However in the first attack in July, a female shop worker was seriously injured after a Russian-made grenade was set off in a store in a densely-populated suburb of Bangkok. Days later a Thai employee was killed and a customer injured when a grenade exploded in another of Tesco's new Bangkok hypermarkets.


Earlier attacks had been blamed on the disgruntled boss of a company that lost a security contract with Tesco. But with the chief suspects in custody since the second bombing, the police have been forced to rethink their investigation.


Tesco is the market leader in Thailand with a 14% share. The supermarket giant's rapid store opening programme in the Far East is an important component in its strategy to have half its total selling space outside the UK by the end of next year.


But while six million Thai shoppers flock to Tesco every month, traditional retailers are in uproar. European store groups have been blamed for the closure of more than 100,000 small grocery shops in the country.


The Thai government, under pressure from traders, has rushed through new legislation to limit 24-hour opening. Further proposals in the pipeline include curb the size and location of new foreign-owned stores and price controls.


Tesco would not comment on the investigation into the bombings, but a spokesman said: 'Tesco has already created 13,000 jobs in Thailand. By next year that figure will be 20,000. We are confident we can work with the Thai government on any new regulations.