Libyan opposition fighters gained control overnight of much of Tripoli, bringing a likely end to Moammar Gadhafi’s 42-year reign, Al Jazeera reports. Sporadic clashes have nevertheless erupted around the Libyan leader’s compound as loyalists resist the rebel advance. Gaddafi’s current location is unknown; he has publicly vowed never to surrender, acknowledging that anti-government forces were moving into the city and predicting it would become another Baghdad. Al Jazeera correspondent Zeina Khodr said that the people of Tripoli “have set up checkpoints, are searching cars and looking for possible Gaddafi supporters,” worried there may be sleeper cells in the capital. Celebrations broke out in the city as the rebel leadership moved into Tripoli. U.S. President Barack Obama has called on Gaddafi to relinquish his power, Reuters reports, and has called on the Transitional National Council rebels to take control after Gaddafi leaves.