SUB-MACHINEGUNS, smoke grenades and ammunition have been discovered in three Speedpost packages in Macau. The weapons were found after a postal worker became suspicious and asked the recipient to open one of the parcels. Four Israeli-made Uzi sub-machineguns, six Austrian Glock pistols, 150 rounds of ammunition, six smoke grenades and two flare bombs were discovered in the parcels sent from Los Angeles to a Taipa Island address. The first two packages, marked 'computer parts' and addressed to a disused garage, were found on Friday. Police sources said the parcels had been addressed to one of the helpers of a high-profile locally organised crime gang, who had been barred from casinos for two years over frequent disturbances during his losing streaks. A third delivery, also addressed to the garage, arrived on Saturday. The seizures are believed to have frustrated attempts by the triad to build a high-powered arsenal. Interpol has been called in to help track down the weapons' source. Hong Kong police last night said they had not been informed. Links between Macau triads and organised crime in Hong Kong came under increased scrutiny in August after an attempt to smuggle two American pistols and bullets aboard the ferry to Macau. Customs spokesman Paul Wai Shing yesterday said metal detectors had been installed at terminals and checks were usually carried out randomly without the need for all passengers to be searched. Marine Department director Ian Dale, who was involved in discussions on ferry services with Macau last week, said authorities had been co-operating on security. In an unrelated case, four men and a woman arrested in a flat in Prince Edward Road, Mongkok, at the weekend are being questioned over the discovery of a converted starting pistol. The four, aged from 17 to 44, were suspected of importing ammunition from China to carry out armed robberies, police said. The pistol, which was found in a handbag on the bed, was allegedly loaded with two rounds of .22 ammunition. A further 29 rounds were also found.