|The protesters blame Gaddafi's government for unemployment, inequality and limits on political freedoms [EPA]
Protesters in Libya have defied a security crackdown and taken to the streets in four cities for a "day of rage," inspired by uprisings in Egypt and Tunisia, reports say.
Several hundred supporters of Muammar Gaddafi, the country's longtime leader, have also reportedly gathered in the capital, Tripoli, on Thursday to counter online calls for anti-government protests.
Their action comes amid reports that at least 14 people have been killed in clashes between pro and anti-government protesters since Wednesday.
New York-based Human Rights Watch said that Libyan authorities had detained 14 activists, writers and protesters who had been preparing the anti-government protests.
Abdullah, an eyewitness in Benghazi, told Al Jazeera that he saw six unarmed protesters shot dead by police on Thursday.
He also claimed that the government released 30 people from jail, paying and arming them to fight people in the street.
Libya has been tightly controlled for over 40 years by Gaddafi, who is now Africa's longest-serving leader.
According to reports on Twitter, the microblogging site, Libya's regime had been sending text messages to people warning them that live bullets will be fired if they join today's protests.
Thursday is the anniversary of clashes that took place on February 17, 2006, in the country's second largest city of Benghazi when security forces killed several protesters who were attacking the city's Italian consulate.
Ibrahim Jibreel, a Libyan opposition member based in Barcelona, told Al Jazeera, "I think the demonstrations are going to be rather serious.
"Libyan people have been oppressed for more than 41 years and they see to the west and to the east of them, people have been able to rise and to change their fate."
At least two people were killed in clashes between Libyan security forces and demonstrators on Wednesday, in the town of al-Baida, east of Benghazi.
The victims were identified as Khaled ElNaji Khanfar and Ahmad Shoushaniya.
Wednesday's deaths come as hundreds of protesters reportedly torched police outposts while chanting: "People want the end of the regime."
At least 38 people were also injured in the clashes, including 10 security officials.
"All the people of Baida are out on the streets," a 25-year-old Rabie al-Messrati, who said he had been arrested after spreading a call for protests on Facebook, said.
Violent protests were also reported earlier in the day in Benghazi.
In a telephone interview with Al Jazeera, Idris Al-Mesmari, a Libyan novelist and writer, said that security officials in civilian clothes came and dispersed protesters in Benghazi using tear gas, batons and hot water.
Al-Mesmari was arrested hours after the interview.
Late on Wednesday evening, it was impossible to contact witnesses in Benghazi because telephone connections to the city appeared to be out of order.
State media reported there were pro-Gaddafi protests too across the country, with people chanting "We sacrifice our blood and souls for you, our leader!" and "We are a generation built by Muammar and anyone who opposes it will be destroyed!"
However, Jibreel said, "There are few who come out in support of the dictator in Libya and they are not going to succeed.
"We are trying to get the voices out of Libya, we are trying to get media attention to the plight of the Libyan people, to get the media to focus on the injustices that are happening in Libya.
"We are urging the governments and diplomatic missions that are in Libya to act as observers, to document the abuses that are going to happen and we know that they are going to happen because this is a totalitarian, brutal regime," he added.
As the wave of unrest spread south and westwards across the country, hundreds of people marched through the streets in the southern city of Zentan, 120km south of the capital Tripoli.
They set fire to security headquarters and a police station, then set up tents in the heart of the town.
Chants including "No God but Allah, Muammar is the enemy of Allah," can be heard on videos of demonstrations uploaded to YouTube.
Independent confirmation was not possible as Gaddafi's government keeps tight control over the movements of media personnel.
In a country where public dissent is rare, plans for Thursday's protests were being circulated by anonymous activists on social networking sites such as Facebook and Twitter.
One Facebook group urging a "Day of Anger" in Libya, which had 4,400 members on Monday, saw that number more than double to 9,600 by Wednesday.
Social media sites were reportedly blocked for several hours through the afternoon, but access was restored in the evening.
Al Jazeera is understood to have been taken off the state-owned cable TV network, but is still reportedly available on satellite networks.
People posting messages on opposition site www.libya-watanona.com, which is based outside Libya, urged Libyans to protest.
"From every square in our beloved country, people should all come together in one city and one square to make this regime and its supporters afraid, and force them to run away because they are cowards," said a post on the website.
Also calling for reforms are some of Libya's eminent individuals. A group of prominent figures and members of human rights organisations have demanded the resignation of Gaddafi.
The demands came in a statement signed by 213 prominent Libyans from different segments of the society, including political activists, lawyers, students, and government officials.
Though some Libyans complain about unemployment, inequality and limits on political freedoms, analysts say that an Egypt-style revolt is unlikely because the government can use oil revenues to smooth over most social problems.
Libya accounts for about 2 per cent of the world's crude oil exports.
Companies including Shell, BP and Eni have invested billions of dollars in tapping its oil fields, home to the largest proven reserves in Africa.
If you are in Libya and have witnessed protests then send your pictures and videos to http://yourmedia.aljazeera.net