Updated at 6.52pm: Secretary for Security Regina Ip Lau Suk-yee said on Wednesday people should express their opinions through legal channels, following the arrest of two people suspected of sending a threatening letter addressed to Chief Executive Tung Chee-hwa. ''Criminal intimidation is a serious crime, '' Mrs Ip said,''The public can express their dissatisfaction but not through threats to attract attention.'' She said the Government had no plans to increase security for senior officials, following the threat.''This criminal intimidation was a stand-alone incident. The public should not fear,'' she said. Government information co-ordinator Stephen Lam Sui-lung said people should be confident of the SAR's security. ''Any acts of intimidation are criminal activities and the police will apply the law forcefully,'' Mr Lam said. ''Hong Kong is a very stable society, so I think we should continue to have confidence in the ability and the professionalism of the police in maintaining stability and law and order in Hong Kong,'' he added. He said the present security arrangements for the people and within government departments were well-established. A police spokeswoman told SCMP.com on Wednesday, that the two suspects were still being detained for further questioning.'' The Apple Daily said the pair allegedly signed the letter as coming from ''Hong Kong's bin Laden'', stating that they were not happy with Mr Tung's leadership. In the letter, they threatened to poison food in supermarket, restaurants and canteens if Mr Tung and top officials did not resign within a month. Wellcome Supermarket chain said on Wednesday that police had seized two contaminated packages linked to poison threats. One pack of Maggi European Snack Instant Noodle in Lai Chi Kok Road and one pack of Cadbury's Cocoa Powder on Queen's Road in Central had been discovered. ''The police have advised us that the threat has been removed as arrests have been made and the products seized,'' Wellcome's Chief Executive Officer Jeff Shaw said.