More than 100 military officials and soldiers have defected from Libya's armed forces in recent days, according to a group of eight military officers, as pressure mounts on leader Muammar Gaddafi to step down.

The high-ranking Libyan army officers appeared at a press conference in Italy on Monday, where they announced that they were part of a group of as many as 120 military officials and soldiers who defected from Gaddafi's side in recent days.

The hastily called news conference was organised by the Italian government for the the eight officers - five generals, two colonels and a major.

"What is happening to our people has frightened us," said one officer, who identified himself as General Oun Ali Oun.

"There is a lot of killing, genocide ... violence against women. No wise, rational person with the minimum of dignity can do what we saw with our eyes and what he asked us to do."

Another officer, General Salah Giuma Yahmed, said Gaddafi's army was weakening day by day, with the force reduced to 20 per cent of its original capacity.

"Gaddafi's days are numbered," said Yahmed.

Abdurrahman Shalgam, the Libyan UN ambassador, who has also defected from Gaddafi, said all 120 military personnel were outside Libya now, but he did not say where they were.