Saif al-Arab, who was sent by his father to help the Libyan security forces with the widespread crackdown on pro-democracy agitators in the eastern parts of Libya, joined the demonstrators in the eastern city of Benghazi Thursday.
Pro-democracy demonstrations inspired by the successful revolutions that deposed decades-long rulers in neighbouring Tunisia and Egypt have engulfed Libya since Feb 14.
Saif al-Arab, who is widely regarded as the most low-profile of Gaddafi's sons, has also hinted that his father would commit suicide or flee to Latin America in the face of rising public outcry over his tyrannical rule, Iran's Press TV reported.
Saif al-Arab is said to have had the backing of combat troops and had military equipment that was dispatched to the eastern parts of the country. The move comes as many intelligence and military officials in the third largest city, Al Bayda, have stepped down, while a major general in the eastern city of Tobruk has castigated Gaddafi's regime for its heavy-handed assault on protesters.
Major General Suleiman Mahmoud, the commander of the armed forces in Tobruk, has stated that he has resigned and has now sided with protesters, adding that soldiers and civilians are being fired upon from aircraft, and this was an important reason for him to join the people.
At least 1,000 people have been killed in Tripoli in airstrikes conducted by the Libyan military in a desperate move to crush the growing protests, according to some reports. Meanwhile, a total of 130 Libyan soldiers have been executed for refusing to open fire on protesters, Press TV said.
Tens of thousands of people have continued to take to the streets of Benghazi and other major cities calling for the ouster of the 68-year-old leader. Gaddafi, who came to power 41 years ago in a bloodless military coup, Tuesday vowed to fight on to his "last drop of blood" and called on his supporters to confront the protesters.