Robert Fisk reports from Libya

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."

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.

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.