Armed militia in military pick-up vehicles on the tarmac of Tripoli international airport. Credit:Reuters Ms Taylor was in Zintan to visit Saif al-Islam Gaddafi, who has been held by the Zintani militia since they captured him in November last year. The ICC charged Muammar Gaddafi, Saif al-Islam, and Libya's former intelligence chief Abdullah al- Senussi with crimes against humanity. Ms Taylor and her ICC colleagues have been placed in ''preventive detention'' for 45 days as Libya investigates the alleged threats to its national security the Zintanis claim she committed. ''We have had a steady deterioration of the security situation in Libya in the past couple of weeks,'' said Dr Mohammad-Mahmoud Ould Mohamedou, head of Middle East and North Africa Program at the Geneva Centre for Security Policy. ''The proliferation of the militia is one of the key elements destabilising Libya - they are young men roaming around, heavily armed and with a sense of entitlement about the paternity of the revolution.

A car travelling in a convoy carrying the UK's ambassador, was hit by a rocket-propelled grenade. Credit:Reuters ''This should have been tamed by the NTC months ago and the militia channelled into civilian organisations.'' Libya is at a crossroads, Dr Ould Mohamedou said, and the continuing threats from the militia calls into question the authority of the national interim government that operates under the auspices of the National Transitional Council. He says Tripoli is in danger of becoming like Baghdad in 2005, with different groups controlling turf and instituting neighbourhood political economies. The government's decision to delay elections for a national congress scheduled for June 19 until July 7 was a symptom of the chaos. ''To be fair to Libya and to the NTC, these are not easy issues, this cannot be engineered overnight - there were no political parties, no civil structures - in effect Gaddafi left a booby-trapped society.''

But the NTC had contributed to the deteriorating security situation by repeatedly capitulating to the militia and as a result, he said, it was ''losing its grip on the situation as the months go by''. Amnesty International's Libya researcher, Diana Eltahawy, has just returned from Libya where she said local militia were taking control from the authorities. ''They have accumulated a large cache of weapons and they are not keen on giving them up, and government efforts to make them join national institutions have failed so far,'' Ms Eltahawy said. ''The militia have been given carte blanche to act however they please - a law passed last month gave them immunity from whatever they may have done in the name of the revolution, which is deeply worrying.'' Both Amnesty International and Human Rights Watch have evidence of abuses committed by the militia, including arrests, detention without charge, torture and extrajudicial executions. ''They have done awful things, they have removed whole communities in both Zintan and near Misrata, looting and burning villages and targeting and punishing whole communities who they accuse of backing the Gaddafi regime,'' Ms Eltahawy said.

Militia had forcibly removed the Mashashia tribespeople from towns near Zintan, while in Misrata more than 12,000 people have been displaced from Tawergha and subject to repeated attacks from armed gunmen. A UN Human Rights Council commission of inquiry reported that Misrata militias had committed crimes against humanity, including the torture and killing of Tawerghans. ''The Misrata thuwar [anti-Gaddafi forces] have killed, arbitrarily arrested and tortured Tawerghans across Libya,'' it concluded in a report released in March. ''The destruction of Tawergha has been done to render it uninhabitable.'' Amnesty International estimates there could up as many as 8000 people being held in Libya without charge or trial, some for as long as nine months. ''Victims of Gaddafi's regime deserve to see justice, but what they are seeing is revenge,'' she said. The much criticised ''Law 38'', which gives immunity to militia for acts committed in the name of the revolution that overthrew Gaddafi also allows judges to use confessions obtained via torture as evidence in court.

There are few cases going ahead, but for those that do, the lawyers, prosecutors and police operate in a dangerous environment, with open threats made against those who challenge the revolutionaries and armed militia maintaining an obvious presence around the court buildings, she said. It is vital that Libya's elections - the first to be held in the country for more than four decades - go ahead as planned in July, Dr Ould Mohamedou said. They may be the circuit breaker that provides a much-needed symbolic break with the old regime.