Libya Pictures: Photos Of Libyans Celebrating Capture Of Seif Al-Islam (PHOTOS)

Supporters of Libyan rebels took to the streets on Monday as they celebrated the capture of Seif al-Islam, Moammar Gaddafi's second-oldest son. Rebel forces came closer to winning the capital of Tripoli and ending the dictator's 42-year rule, The Associated Press reports.

"It's over, frizz-head," chanted hundreds of jubilant men and women massed in Green Square, using a mocking nickname of the curly-haired Gadhafi. The revelers fired shots in the air, clapped and waved the rebels' tricolor flag. Some set fire to the green flag of Gadhafi's regime and shot holes in a poster with the leader's image.

The startling rebel breakthrough, after a long deadlock in Libya's 6-month-old civil war, was the culmination of a closely coordinated plan by rebels, NATO and anti-Gadhafi residents inside Tripoli, rebel leaders said. Rebel fighters from the west swept over 20 miles (30 kilometers) in a matter of hours Sunday, taking town after town and overwhelming a major military base as residents poured out to cheer them. At the same time, Tripoli residents secretly armed by rebels rose up.

Despite the celebration, Gaddafi's location remains unknown, and fighting in Tripoli continues. CNN correspondent Sara Sidner reported that snipers near Tripoli's Green Square were firing "at anyone that moved."

Some journalists are trapped at the Rixos Al Nasr hotel, unable to leave because of machine gun-fire outside the hotel.

Read The Huffington Post's live blog for the latest from Libya.

LOOK: Pictures of Libyans celebrating: