Protesters demanding Moammar Gadhafi's ouster came under a hail of bullets Friday when pro-regime militiamen opened fire to stop the first significant anti-government marches in days in the Libyan capital. The Libyan leader, speaking from the ramparts of a historic Tripoli fort, told supporters to prepare to defend the nation.
Witnesses reported multiple deaths from gunmen on rooftops and in the streets shooting at crowds with automatic weapons and even an anti-aircraft gun.
"It was really like we are dogs," one man who was marching from Tripoli's eastern Tajoura district told The Associated Press. He added that many people were shot in the head, with seven people within 10 yards of him cut down in the first wave.
Also Friday evening, troops loyal to Gadhafi attacked a major air base east of Tripoli that had fallen into rebel hands.
A force of tanks attacked the Misrata Air Base, succeeding in retaking part of it in battles with residents and army units who had joined the anti-Gadhafi uprising, said a doctor and one resident wounded in the battle on the edge of opposition-held Misrata, Libya's third-largest city, about 120 miles from the capital.
The opposition captured two fighters, including a senior officer, and still held part of the large base, they said. Shooting could still be heard from the area after midnight. The doctor said 22 people were killed in two days of fighting at the air base and an adjacent civilian airport.
In Washington, President Barack Obama signed an executive order Friday freezing assets held by Libyan leader Moammar Gadhafi and four of his children in the United States. The Treasury Department said the sanctions against Gadhafi, three of his sons and a daughter also apply to the Libyan government.
Obama said the U.S. is imposing unilateral sanctions on Libya because continued violence there poses an "unusual and extraordinary threat" to America's national security and foreign policy.
A White House spokesman said it is clear that Gadhafi's legitimacy has been "reduced to zero" — the Obama administration's sharpest words yet. The U.S. also temporarily abandoned its embassy in Tripoli as a final flight carrying American citizens departed from the capital.
The U.N. Security Council met to consider possible sanctions against Gadhafi's regime, including trade sanctions and an arms embargo. Secretary-General Ban Ki-moon urged it take "concrete action" to protect civilians in Libya, saying "the violence must stop" and those responsible for "so brutally shedding blood" must be punished.
But Gadhafi vowed to fight on. In the evening, he appeared before a crowd of more than 1,000 supporters in Green Square and called on them to fight back and "defend the nation."
"Retaliate against them, retaliate against them," Gadhafi said, speaking by microphone from the ramparts of the Red Castle, a Crusader fort overlooking the square. Wearing a fur cap, he shook his fist, telling the crowd: "Dance, sing and prepare. Prepare to defend Libya, to defend the oil, dignity and independence."
He warned, "At the suitable time, we will open the arms depot so all Libyans and tribes become armed, so that Libya becomes red with fire."
The crowd waved pictures of the leader and green flags as he said, "I am in the middle of the people in the Green Square. ... This is the people that loves Moammar Gadhafi. If the people of Libya and the Arabs and Africans don't love Moammar Gadhafi then Moammar Gadhafi does not deserve to live."
Gadhafi's son, Seif al-Islam, told foreign journalists invited by the government to Tripoli that there were no casualties in Tripoli and that the capital was "calm ... Everything is peaceful. Peace is coming back to our country."
He said the regime wants negotiations with the opposition and said there were "two minor problems" in Misrata and Zawiya, another city near the capital held by the opposition.
There, he said, "we are dealing with terrorist people." But he said he hoped to reach a peaceful settlement with them "and I think by tomorrow we will solve it."
Earlier Seif was asked in an interview with CNN-Turk about the options in the face of the unrest. "Plan A is to live and die in Libya, Plan B is to live and die in Libya, Plan C is to live and die in Libya," he replied.
The marches in the capital were the first major attempt by protesters to break a clampdown that pro-Gadhafi militiamen have imposed on Tripoli since the beginning of the week, when dozens were killed by gunmen roaming the street, shooting people on sight.
In the morning and night before, text messages were sent around urging protesters to stream out of mosques after noon prayers, saying, "Let us make this Friday the Friday of liberation," residents said. The residents and witnesses all spoke on condition of anonymity for fear of retaliation.
In response, militiamen set up heavy security around many mosques in the city, trying to prevent any opposition gatherings. Armed young men with green armbands to show their support for Gadhafi set up checkpoints on many streets, stopping cars and searching them. Tanks and checkpoints lined the road to Tripoli's airport, witnesses said.
After prayers, protesters flowed out of mosques, converging into marches from several neighborhoods, heading toward Green Square. But they were hit almost immediately by militiamen, a mix of Libyans and foreign mercenaries.
"We can't see where it is coming from," another protester from Tajoura district — several miles (kilometers) from Green Square — said of the gunfire. "They don't want to stop." He said a man next to him was shot in the neck.
In the nearby Souq al-Jomaa district, witnesses reported four killed as gunmen fired from rooftops. "There are all kind of bullets," said one man in the crowd, screaming in a telephone call to the AP, with the rattle of gunfire audible in the background. Another protester was reported killed in the Fashloum district. The reports could not be independently confirmed.
French president Nicolas Sarkozy
French president Nicolas Sarkozy has stated during a news conference that Libyan leader Muammar al-Gaddafi "must leave," calling the leader to step down. His comments were made during a press conference with the Turkish president Abdullah Gül in . Sarkozy also stated that military action to remove Gaddafi isn't ruled out.

"Our stance is clear. Mr Gaddafi must go. The systematic violence against the Libyan people is unacceptable and will be the subject of investigations and sanctions. Regarding a military intervention ... France would consider any initiative of this type with extreme caution and reserve," said Sarkozy. The United Kingdom is also calling for an arms embargo along with an investigation into war crimes be conducted against Gaddafi.

Sarkozy's call on Gaddafi to step down comes after violence on Friday alone has left at least five people dead in Tripoli, the capitol of Libya, when security personnel fired on demonstrators. At least 500 people are suspected to have been killed in Tripoli with over 2,000 injured. Gunshots were heard in several parts of the city on Friday. Navi Pillay, head of the human rights division of the United Nations says thousands in Libya could have been killed since the uprising began. Human Rights Watch puts the death toll at 300.

"We think this needs to be brought to the International Criminal Court. We also think that people who still cooperate with Gadhafi should be punished," added Sarkozy.

Reports say security forces loyal to Gaddafi have used rocket propelled grenades, snipers, anti aircraft guns and foreign mercenaries to repel protesters. Gaddafi blames Osama bin Laden and people on hallucinogenic drugs for the mass  protests in the country. "(The protesters') ages are 17. They give them pills at night, they put hallucinatory pills in their drinks, their milk, their coffee, their Nescafe," he said on Thursday.

In a speech that aired on Libyan State TV today, Gaddafi said to supporters in Green Square in Tripoli, "We can defeat any aggression if necessary and arm the people. Prepare to defend the nation and defend the oil. We can retaliate against them the opposition. You, the youth, be comfortable... dance, sing, stay up all night."