According to CNN, Interior Minister Abdul Fattah Younis al Abidi quit Monday after hearing that some 300 civilians have been killed in Libya's eastern city of Benghazi. He accused Gaddafi of planning to attack civilians on a wide scale.
"Gaddafi told me he was planning on using airplanes against the people in Benghazi, and I told him that he will have thousands of people killed if he does that," Abidi was quoted as saying Wednesday.
A defiant Gaddafi, who has been in power since 1969, in a televised speech Tuesday, refused to step down despite mass uprising and vowed to die "a martyr" in his country.
According to international organisations, around 500 people have been killed and up to
4,000 injured in clashes with government forces since protests against Gaddafi's regime began Feb 15.
Abidi said he now supports the people and the revolution.
Describing Gaddafi as "a stubborn man" who will not give up, Abidi said "he (Gaddafi) will either commit suicide or he will get killed", the media report said.
Abidi also hoped the revolution will succeed "in a matter of days or hours", and he called on Libyan security forces "to join the people in the intifada (uprising)".
He said "many members" of the security forces have already left the government and the entire eastern part of the country is no longer under Gaddafi's control.
Libyan ambassador to the US, Ali Aujali, also called for Gaddafi to resign, joining a chorus of Libyan officials, including the deputy ambassador to the UN, who said they now work for the Libyan people and not for Gaddafi.