TRIPOLI, Libya (AP) - Libyan leader Moammar Gadhafi was nowhere to be found Monday as his 42-year rule teetered on the brink of collapse.
Months of NATO airstrikes have left his Bab al-Aziziya compound in Tripoli largely demolished. Most of his security forces fled or surrendered when rebel forces rolled into the capital Sunday night and took control of most of the city. Three of his sons were under arrest.
A mood of joy mixed with trepidation settled over the capital, with the rebels still fighting pockets of fierce resistance from regime loyalists firing mortars and anti-aircraft guns. Rebel spokesman Mohammed Abdel-Rahman, who was in Tripoli, said the "danger is still there" as long as Gadhafi remains on the run.
"The real moment of victory is when Gadhafi is captured," Mustafa Abdel-Jalil, head of the rebel National Transitional Council, told a news conference in the opposition's de facto capital of Benghazi, hundreds of miles east of Tripoli. He said the rebels have no idea where Gadhafi is and whether he is even in Tripoli. An Obama administration official said the U.S. had no indication that Gadhafi had left Libya.
Gadhafi's forces remained active, firing off a short-range Scud missile Monday near Sirte, Gadhafi's hometown and one of the few remaining cities still under his control, said U.S. military officials, who spoke on condition of anonymity to discuss military operations. It was unclear where the missile landed or if anyone was hurt.
President Barack Obama said the situation in Libya reached a tipping point in recent days after a five month NATO-led bombing campaign. However, he acknowledged that the situation remained fluid and that elements of the regime remained a threat.
The Obama administration official said U.S. officials and NATO partners had not been in contact with Gadhafi during the siege on Tripoli. However, the official said American and NATO representatives, as well as Libyan rebels, had all been in contact with people around Gadhafi, mostly those looking for a way out.
NATO vowed to keep up its air campaign until all pro-Gadhafi forces surrender or return to their barracks. The alliance's warplanes have hit at least 40 targets in and around Tripoli in the past two days - the highest number on a single geographic location since the bombing started in March, NATO said.
A day after the rebels rode into the city of 2 million, the situation remained volatile. Even though rebels claimed they were in control of most of Tripoli, they still appeared to be on the defensive, ducking for cover during frequent clashes with regime fighters. Throughout the day, the rebels sent reinforcements to the city from the north, south and southeast, and a rebel field commander said more than 4,000 fighters were part of the final push to bring down the regime.
The Obama administration official said the U.S. believes 90 percent of the capital is under rebel control, while regime loyalists still control Sirte and the southern city of Sabha. The official spoke on the condition of anonymity because they were not authorized to speak publically.
The Scud missile fired near Sirte was launched at about 1:15 p.m. CDT, U.S. officials said.
It was only the second Scud missile fired during this year's conflict. On Aug. 15, Libyan government forces launched one near Sirte that landed in the desert outside Brega, injuring no one.
Intense gun battles erupted throughout the day and the capital was too unstable for any mass celebrations in the streets.
Clashes broke out early in the day at Gadhafi's Bab al-Aziziya compound when government tanks emerged from the complex and opened fire at rebels trying to get in, according to the rebel spokesman Abdel-Rahman and a neighbor.
Moammar al-Warfali, whose family home is next to the Gadhafi compound, said there appeared to be only a few tanks belonging to the remaining Gadhafi forces who have not fled or surrendered.
"When I climb the stairs and look from the roof, I see nothing at Bab al-Aziziyah. It is totally deserted except for the house which was raided by U.S. in 1986. Nothing else is there. Gadhafi can't be there," he said. "NATO has demolished it all and nothing remained."
But Abdel-Rahman said Gadhafi still has forces to be reckoned with.
"We know that until now, Tripoli is encircled by Gadhafi brigades positioned at the outskirts of the capital, in camps, such as al-Yarmouk in the south of Tripoli. They can be in the middle of the city in half an hour."
Still, revelers flocked to Green Square, the symbolic heart of the fading Gadhafi regime. They flashed the "V" for victory sign and motorists circled the plaza, honking horns and waving rebel flags.
"We came out today to feel a bit of freedom," Ashraf Halati, a 30-year-old Tripoli resident, said as he and four of his friends watched several hundred people celebrating at Green Square. "We still don't believe that this is happening."
Late Sunday night, rebels took over Green Square, which they have been calling Martyrs' Square, restoring the name it had before Gadhafi's regime took power more than four decades ago. Google's map of Tripoli has already adopted the new name. The opposition also took up the pre-Gadhafi flag of Libya as their own at the start of their uprising six months ago.
On Monday, rebels manned checkpoints on the western approaches to the city, handing out candy to motorists and inquiring about their destinations.
Most of the city, a metropolis of some 2 million people on the Mediterranean coast, was on edge. Stores were shuttered and large areas were lifeless, including the old gold market, in the past a draw for tourists.
But the rebels' optimistic mood of the morning quickly changed. By mid-afternoon, the college came under heavy fire. Snipers from nearby high-rises aimed at motorists speeding by. An anti-aircraft gun pounded the compound, creating a deafening noise. A handful of rebel fighters inside seemed jumpy and unsure what to do.
Gadhafi loyalists also launched attacks in two other areas of Tripoli, said Ashraf Hussein, a rebel fighter who sat pressed against an inner wall of the compound for safety.
Drivers trying to evade sniper fire ducked into side streets, or stopped at rebel checkpoints to find out whether the next stretch was safe. Booms of mortar rounds and small rockets reverberated across the city, mixed with battle cries of "Allahu akbar," or God is Great.
Later Monday, another battle erupted around a school where rebels and journalists had set up camp. Rebels fired small rockets, and Gadhafi troops responded with mortar shells.
The fighting made clear that taking full control of Tripoli will be difficult, especially as long as Gadhafi has not surfaced.