over the, quote, "spilling of blood" by government forces, but the libyan government spokesman moussa ibrahim offered a different reason. >> the information we have is that he's tired, he's exhausted and he resigned, that's it. when something happens we will talk about it. >> brown: qaddafi's former spy chief has long been suspected of being involved in the 1988 bombing of pan am flight 103 over lockerbie, scotland that killed more than 250 people. the regime's opponents also blame him for numerous assassinations of libyan dissidents in exile. british officials said kusa is now being debriefed. and they insisted he has not received immunity from any potential british or international charges. britain's foreign secretary william hague said kusa's defection has put increased pressure on the libyan leader. >> his resignation shows that qaddafi's regime, which has already seen significant defections to the opposition, is fragmented, under pressure and crumbling from within. qaddafi must be asking himself, "who will be the next to abandon him?" >> brown: that was the official response in washingto