Libyan rebels have taken over Col Muammar Gaddafi's compound in Tripoli, one of the final areas under the Libyan leader's control.Heavily armed fighters had earlier streamed into the capital in dozens of pick-up trucks to attack the compound.TV footage showed smoke rising from buildings across the city, and the sound of shelling could be heard.Col Gaddafi's son Saif al-Islam appeared in Tripoli overnight, hours after rebels said he had been captured.A rebel leader said his appearance was embarrassing, but would not stop their advance.On Tuesday morning, rebel commanders said they would concentrate all of their efforts on attacking the the heavily fortified Bab al-Aziziya compound.The BBC's Rupert Wingfield-Hayes in western Tripoli says they believe the key to ending this conflict is to capture or kill Col Gaddafi.Footage from Sky News showed gangs of rebels gathered about 50m (164ft) from the compound dressed in civilian clothes, some armed with rifles, others unarmed. The sound of shells exploding could be heard nearby.Later reports said hundreds fighters had breached one of the gates of the compound, and that gangs were inside the compound firing guns into the air to celebrate.