Robert Fisk with the first dispatch from Tripoli - a city in the shadow of death

Gunfire in the suburbs – and hunger and rumour in the capital as thousands race for last tickets out of a city sinking into anarchy

Up to 15,000 men, women and children besieged Tripoli's international airport last night, shouting and screaming for seats on the few airliners still prepared to fly to Muammar Gaddafi's rump state, paying Libyan police bribe after bribe to reach the ticket desks in a rain-soaked mob of hungry, desperate families. Many were trampled as Libyan security men savagely beat those who pushed their way to the front.

Among them were Gaddafi's fellow Arabs, thousands of them Egyptians, some of whom had been living at the airport for two days without food or sanitation. The place stank of faeces and urine and fear. Yet a 45-minute visit into the city for a new airline ticket to another destination is the only chance to see Gaddafi's capital if you are a "dog" of the international press.

There was little sign of opposition to the Great Leader. Squads of young men with Kalashnikov rifles stood on the side roads next to barricades of upturned chairs and wooden doors. But these were pro-Gaddafi vigilantes – a faint echo of the armed Egyptian "neighbourhood guard" I saw in Cairo a month ago – and had pinned photographs of their leader's infamous Green Book to their checkpoint signs.

There is little food in Tripoli, and over the city there fell a blanket of drab, sullen rain. It guttered onto an empty Green Square and down the Italianate streets of the old capital of Tripolitania. But there were no tanks, no armoured personnel carriers, no soldiers, not a fighter plane in the air; just a few police and elderly men and women walking the pavements – a numbed populace. Sadly for the West and for the people of the free city of Benghazi, Libya's capital appeared as quiet as any dictator would wish.

But this is an illusion. Petrol and food prices have trebled; entire towns outside Tripoli have been torn apart by fighting between pro- and anti-Gaddafi forces. In the suburbs of the city, especially in the Noufreen district, militias fought for 24 hours on Sunday with machine guns and pistols, a battle the Gadaffi forces won. In the end, the exodus of expatriates will do far more than street warfare to bring down the regime.

I was told that at least 30,000 Turks, who make up the bulk of the Libyan construction and engineering industry, have now fled the capital, along with tens of thousands of other foreign workers. On my own aircraft out of Tripoli, an evacuation flight to Europe, there were Polish, German, Japanese and Italian businessmen, all of whom told me they had closed down major companies in the past week. Worse still for Gaddafi, the oil, chemical and uranium fields of Libya lie to the south of "liberated" Benghazi. Gaddafi's hungry capital controls only water resources, so a temporary division of Libya, which may have entered Gaddafi's mind, would not be sustainable. Libyans and expatriates I spoke to yesterday said they thought he was clinically insane, but they expressed more anger at his son, Saif al-Islam. "We thought Saif was the new light, the 'liberal'", a Libyan businessman sad to me. "Now we realise he is crazier and more cruel than his father."

The panic that has now taken hold in what is left of Gaddafi's Libya was all too evident at the airport. In the crush of people fighting for tickets, one man, witnessed by an evacuated Tokyo car-dealer, was beaten so viciously on the head that "his face fell apart".

Talking to Libyans in Tripoli and expatriates at the airport, it is clear that neither tanks nor armour were used in the streets of Tripoli. Air attacks targeted Benghazi and other towns, but not the capital. Yet all spoke of a wave of looting and arson by Libyans who believed that with the fall of Benghazi, Gaddafi was finished and the country open to anarchy.

The centre of the city was largely closed up. All foreign offices have been shut including overseas airlines, and every bakery I saw was shuttered. Rumours abound that members of Gaddafi's family are trying to flee abroad. Although William Hague's ramblings about Gaddafi's flight to Venezuela have been disproved, I spoke to a number of Libyans who believed that Burkina Faso might be his only viable retreat. Two nights ago, a Libyan private jet approached Beirut airport with a request to land but was refused permission when the crew declined to identify their eight passengers. And last night, a Libyan Arab Airlines flight reported by Al Jazeera to be carrying Gaddafi's daughter, Aisha, was refused permission to land in Malta.

Gaddafi is blamed by Shia Muslims in Lebanon, Iraq and Iran for the murder of Imam Moussa Sadr, a supposedly charismatic divine who unwisely accepted an invitation to visit Gaddafi in 1978 and, after an apparent argument about money, was never seen again. Nor was a Lebanese journalist accompanying him on the trip.

While dark humour has never been a strong quality in Libyans, there was one moment at Tripoli airport yesterday which proved it does exist. An incoming passenger from a Libyan Arab Airlines flight at the front of an immigration queue bellowed out: "And long life to our great leader Muammar Gaddafi." Then he burst into laughter – and the immigration officers did the same.