Irish citizens who fled Libya overnight have said there was chaos in Tripoli when an Air Corps plane was forced to leave the airport without any passengers.
As officials planned a second evacuation attempt of passport holders from the troubled north African state, a small number of Irish passengers landed at Gatwick Airport in London.
Helena Sheehan, a university professor from Dublin, said she had just experienced some of the worst hours of her life.
"Libya is descending into hell," she said as she landed in London.
"The airport is like nothing I've ever seen in my whole life.
"It's absolute chaos. There's just thousands and thousands of people trying to get out."
There are about 70 Irish citizens in Libya, with 54 of those in Tripoli - the majority are said to be in the airport.
The Government's Casa aircraft spent four hours at the airfield yesterday, but was prevented from airlifting the Irish citizens by Libyan security. It later returned to Malta empty.
The Department of Foreign Affairs revealed efforts to land the Casa with a small crisis management team had resumed.
It stated while a small number of Irish citizens had left Tripoli, it could not confirm the exact numbers until passengers landed and made contact with officials.
Ms Sheehan, 66, said she was visiting the country to give a lecture but had been "abandoned" by her hosts when trouble broke out.
She said she witnessed burning buildings and gunfire and described the atmosphere in the airport, where thousands of people, mainly Arabs, were trying to get home to their own countries, as "horrendous".
"The thing I'll remember longest is just the airport, this horrendous disruption of people's lives," she added.
John McDevitt, from Co Wicklow, said there was absolute chaos at the airport in Tripoli with thousands of people desperate to get out.
He revealed he had expected to board the Casa last night, but was taken to London by the British Foreign Office when the Irish aircraft was forced to leave without any passengers.
"We were very, very lucky indeed," said Mr McDevitt. "There is a lot of fear obviously the way things are unfolding very fast there. Personally I feel the airport itself will get closed down because the regime is now in desperate straits and I think it could become very, very dangerous," he said.
"The streets themselves are already very volatile."
Karen Willoughby, 30, flew in to Gatwick on her way home to Galway with her husband and their seven-month-old son.
"We went to the airport the day before yesterday at 6am and got going at 5am today Libya time," she said.
"I'm glad to be home, it was getting scary.
"They say tonight will be a big night there and expect that the airport will be closed. It's just crazy."
Another passenger, who did not want to be named, said he had been trying to get out of Libya and home to Dublin for "three or four" days.
However he said he believed the authorities had done all they could to get people out.
He said: "It was mayhem, but I think people were quite helpful."
He said he had not felt like he was in danger himself, but added that the sounds of gunfire and violence at night were "hellish".
"You would just see a lot of people armed, we were instructed to stay inside," he said.
The evacuation is being co-ordinated by Pat Hennessy, the Irish ambassador in Rome who is accredited to Libya.
Anyone who has any concerns over family or friends in Libya can contact its Crisis Centre on 01 4180222.
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.