More than six men with triad links were being questioned in Macau last night over the bomb blast which injured 15 police and journalists. Meanwhile, police stepped up security and tourism officials reported increased concerns as a result of the blast, the first to target non-security or non-government personnel. The authorities played down reports that anyone had been detained, but police sources said several men had been 'brought in for interrogation'. They said the suspects had connections to the 14K triad society. Explaining the lack of information about arrests, the source said: 'This investigation is like an octopus and we don't just want to chop off one leg and let the rest live. Our intention is to chop off all eight legs.' Three police officers and seven journalists, injured in what detectives have described as a 'premeditated and deliberate attack by organised criminals', remained in hospital last night. None was in serious condition. The bombers, who lured police and journalists to the scene with a first blast then detonated a second minutes later - apparently by remote control - have been dubbed 'terrorists' by the Macau Governor, General Vasco Rocha Vieira, who is visiting the former Portuguese African colony of Cape Verde. An official said several overseas tour operators had called to check on the security situation and ferries from Hong Kong were quieter than usual. The Judiciary Police denied reports that two teams of mainland police had been sent to help hunt the bombers.