ABBOTTABAD - A day after getting clearance from Pakistan, a team CIA investigators Friday visited and searched the compound where Osama bin Laden was killed. Sources said a group of CIA investigators visited the compound on Friday afternoon after flying in via a helicopter. Eyewitnesses said the helicopter fly in around 12:45pm in the afternoon amid tight security in the area. Media was denied access to the compound. Police and intelligence sources confirmed that a group of special guests had landed at the military academy helipad, before making their way to the compound in two double-cabin cars with a heavy security cordon. The surrounding area was too abuzz with security personnel, with armed men standing on guard atop roof tops and manning check points. Investigators spent almost four hours at the compound before flying back around five in the evening. The visit signals a step towards cooperation amid intense US diplomatic efforts to shore up strained relations with Pakistan in the aftermath of the raid. The CIA has also been granted access to materials that Pakistans security forces have recovered from the compound. The visit came right after Hillary Clintons five-hour stop-over in Islamabad.