THE trouble actually started with a small demonstration about noon last Sunday, the anniversary of the 17-point agreement under which the Dalai Lama handed over Tibet to Beijing. Five men circled Tibet's holiest temple, the Jokhang, waving banners which read ''Chinese Out, Free Tibet'', and carrying the former national flag of Tibet. Plain-clothed police ran after them, but the men seemed to get away. I was on the top of the temple at the time and could see police on rooftops focusing video cameras on the faces of the demonstrators. About noon on Monday, people began gathering in Barkhor, the main square in which the Jokhang is situated. By 12.30 pm 150 people were demonstrating. The word was that the authorities had given their permission for the demonstration because it had an economic basis - that is, a protest against inflation. But later the Chinese Government said it was totally illegal. The first protesters were Tibetan traders. They were later joined by old men and women turning prayer wheels, and the khampas - sturdy mountain people from the north - with red or black headdresses and sheathed daggers, and poor villagers with cloaks andwoven woollen boots. The protesters carried banners in Tibetan and Chinese demanding lower prices for petrol, yak butter and tsampa (roasted ground barley, the Tibetan staple food). By 1 pm, the crowd had reached about 200. The demonstrators called to onlookers and Tibetans watching from the upper windows to join the march. Younger Tibetans in baseball caps and training shoes started jeering at Tibetan and Chinese who had not already closed their shops or stalls. One stall table was overturned. Chinese merchants began boarding up their shops. Again, I was on the roof of the Jokhang with the monks. I could see the police on the rooftop of every government building. The streets were sparsely scattered with police. At this point, plain-clothed police started telling Westerners to return to theirhotels. About 300 demonstrators were calling up to the monks for leadership. The monks went back inside, looking nervous for they had noticed Tibetan spies, collaborators with the Chinese-dominated local government, entering the temple. With banners aloft, the crowd marched towards the People's Park, until they reached a government building where they believed six dissidents were being held. About 100 men started rattling the gates of the compound. Inside, about 60 police held the gate.Behind them stood about 10 riot police with helmets and shields, but no sticks. Police had now had to duck small stones being thrown at them. Then the crowd headed towards the Potala Palace, the former home of the Dalai Lamas which dominates Lhasa. A few metres away from the crowd, about 20 youths surrounded eight Tibetan policemen.The youths spat on the police, practically turning their dark uniforms white. The demonstrators circled the Potala, then continued on to the Holiday Inn several kilometres away. This is where a mission of Beijing-based European Community ambassadors had been staying until the previous day. It was now about 3 pm, and the demonstration had grown to a crowd of about 700 people, perhaps half of them serious demonstrators. The rest were children and hangers-on, many of them laughing and chatting. At the hotel, Western tourists recorded the demonstration with film and video cameras, and the Tibetans were playing for the foreigners' attention. An army truck came thundering down the road, packed with soldiers carrying machine guns, but I did not seethe truck again. Five o'clock, and the crowd was back at the Barkhor. There were about 1,500 to 2,000 people in the march at this stage. Most shops in the square had packed up. Suddenly, one section of the crowd started shouting ''Free Tibet! Chinese out! Freedom now!'' The demonstrators gathered in front of the Public Security Bureau offices, a Chinese hospital, Tibetan government buildings and residences of high-ranking officials. I saw stones thrown at police headquarters. The police were relatively passive and had no riot gear, but I did see five people arrested and bundled up into the backs of trucks. About 20 people were arrested in all, according to reports of various witnesses. In addition, about 16 Westerners were arrested. Their film and passports were taken, they were detained and released after some hours. Some had their visas cancelled and were ordered to leave Lhasa within days. Tibetans seemed heartened by the presence of Westerners. At one point an old Tibetan woman took my hand and waved it in the air. But they later panicked after reports of bloodshed circulated. There was talk of a handful of people being killed, but it was impossible to get confirmation. About 6.40 pm, two large trucks appeared at the Barkhor. Moments later, there were loud explosions from the square. The crowd started to run, screaming. Then they slowed to a walk and began chanting until tear-gas canisters rained down from all sides. The police fired their tear-gas canisters at protesters. Some protesters stoned police vehicles. The air was full of gas. I escaped down an alley and ducked into a packed restaurant. Children were covering their heads with their hands to protect themselves from the gas. Some older women were crying. The explosions became louder and louder until the canisters started landing at the restaurant's door. Many of the Westerners were still ordering food. A group of Israelis said they could identify the sound of machine-gun fire disguised by the explosion of fire-crackers. The Hongkong people in the restaurant were particularly worried. I ran back to my hotel, only to find the door locked. I banged to be let in. Tear-gas canisters landed at my feet. I kicked the door. Even the police got caught in their own gas: two policemen behind me hit the ground to escape the tear-gas canisters. When I finally got in to the hotel, plain-clothed agents told me: ''You have been very bad. You went out.'' In the midst of this mayhem, a tourist arrived at the hotel in a taxi, got out and, oblivious to the tear-gas, went around looking for a money-changer to change US dollars into the local currency so he could pay his cab driver. It was about 7.30 now. Foreigners were not allowed out of the hotel. I could still hear the machine-gun fire, and there was no one in the streets. The explosions were further and further away. By about 9.30 pm, things were calm for the most part - yet one could hear the sound of tear-gas explosions and gunfire every five or 10 minutes until about 11 pm. On Tuesday, the police posted notices in hotels saying foreigners could face up to 15 days in jail for spreading false information, interfering with the police or joining demonstrations. Hotel-keepers were warned to control their guests. A demonstration was supposed to start at 10 am on Tuesday, but did not begin until two hours later. All the shops were closed. The demonstration never really got off the ground because the police dispersed protesters with tear-gas grenades before the crowd could grow to more than about 150. The grenades give off shrapnel, and I saw a child badly wounded in the face and a man whose leg had been badly cut. Even so, the demonstrations did not actually die down until late afternoon. At week's end, the local government was apparently in meetings trying to decide on a detailed statement reconstructing, in their view, the events of the past few days, and attempting to decide for political purposes how to classify the demonstrations. There was talk of Tibetans being arrested each day, but it was not possible to confirm these reports. Many Tibetan shops in the Barkhor remained closed. The atmosphere was tense. The square and the Jokhang were empty. On Friday, police questioned me for six hours, but they never really got to the point. I was allowed to proceed with my previous travel schedule.