Government's traditional non-interventionist stance - except at the behest of big business - had created a climate rich in commercial opportunity but uncongenial to labour relations. Even so it was apparent, from a sequence of events in the early months of 1967, that at least some genuine industrial disputes were being exploited for political gain. Taking their cue from the Cultural Revolution sweeping across China, local dissidents inflamed grievances in key sectors of Hong Kong industry, producing an atmosphere of mounting tension and concern.

Prime targets for their intervention were four taxi companies, a textile factory, a cement company and the Hong Kong Artificial Flower Works. The Hong Kong Seamen's Union was simultaneously engaged in a dispute with a shipping company and an official boycott of the Government Seamen's Recruiting Office. In each case identical tactics were employed. Workers were intimidated, and attempts to settle their complaints were frustrated by the injection of political issues that had not been their original concern.

Lists of demands requiring 'unconditional' acceptance were followed by rowdy demonstrations designed to intimidate management. Offers of mediation by the Labour Department were rejected as 'unwelcome meddling'. At least one press photographer was attacked for photographing such a demonstration.

On May 6, 1967 some 21 dismissed workers of the Artificial Flower Works in San Po Kong were arrested by police for ignoring repeated warnings and preventing the removal of goods from the premises. Reaction in the left-wing press was immediate. The government and police were accused of persecution and brutality.

Further picketing and demonstrations at the San Po Kong factory culminated in a more serious clash with police on May 11, sparking a riot which spread to neighbouring areas of Kowloon, where buses and other vehicles were set on fire and government offices and staff quarters were looted. A curfew was imposed on that and the two following nights.

The campaign of intimidation spread to Hong Kong Island. Delegations from branches of Mainland-owned department stores, from left-wing publications and from trade unions - most identically attired in white shirts and black trousers - converged at the gates of Government House, waving the little red books so conspicuous among the Red Guards in China.

Powerful loudspeakers, mounted on the Bank of China building, broadcast propaganda at high volume and provoked the government into responding by mounting a battery of even louder speakers on the roof of Beaconsfield House, directly above the DIS' office, playing the contemporary equivalent of today's Canto-pop music at deafening decibels. Working conditions in the heart of Hong Kong's business and banking centre became all but intolerable; but nowhere more so than in ISD.

Bob Sun recalls: "There was rioting in Kowloon and the government had to order a curfew. A command centre under Assistant Commissioner Sutcliffe was set up at the Kowloon Police Headquarters. As the GIS Press Officer, I moved to the Police command centre for my news operations. Latest information was released via teleprinter back to ISD for forwarding to the media.

"In the middle of the evening, Sutcliffe decided to send out a Police squad to reconnoitre. Superintendent Godber (later of corruption notoriety) was ordered to lead the party. He went into the armoury to get his gun. However, he openly admitted he had not carried one for such a long time that he would not know how to handle it. I went along with them.

"It was pretty quiet everywhere we patrolled, except when we reached Nathan Road in Tsim Sha Tsui. No sooner than I got out from the Police vehicle, down came a rattan chair from an upper storey. It landed squarely to my right. As my reflex made me dodge to the left, a bottle filled with water nearly nicked my head. It popped beside me. If either of them had been a direct hit, it could have been fatal.

"Back at the command centre, it was 4am. A voice came over the speaker. It was the Police Commissioner Tyrer speaking from Arsenal Street. He said: 'Ask Bob Sun to go to Yau Ma Tei (police division) to read the riot act to the four correspondents of CBS, Time and NBC. Then escort them to the Star Ferry concourse to await the first ferry back to the Island.' We did not have to wait long for the ferry service to resume. That was the very first time in my life I crossed the harbour at the crack of dawn."

Michael Stevenson, then Deputy Director of Information Services, formed a special team to respond to the propaganda programme mounted by the dissidents. Their prime objective was to preserve the morale of the community and to win public support for the measures government was compelled to impose in order to maintain security.

In July 1967 a mob attack on a police post and the Rural Committee Office at Sha Tau Kok, left five Police dead and 11 wounded. Control of the sensitive border area shifted under the umbrella of joint police-military operations and Peter Moss, Gerry Xavier and photographer Gatlin Lin were attached as the GIS contingent to the so-called PolMil headquarters at Sek Kong.

Irene Yau, then an Executive Officer on secondment to GIS, recalls: "I spent the first part of the morning reading out the Chinese papers in the English language in a very dark, smoky room, to a group of gentlemen who included Jack Cater, Mike Stevenson, Bob Locking and some army officers in uniform. They were a pretty high powered lot.

"I joined government as a housing assistant, and then got into the Executive Officer grade. At the height of the disturbances I was posted to GIS, where I remained. One morning I saw a curly, blond guy in the group, and learned he was David Ford. Later the group was joined by a moustachioed gentlemen with a monacle and a long cigarette holder, whose name was John Slimming."