TRIPOLI, Libya — NATO airstrikes targeted the center of Moammar Gadhafi’s seat of power early today, destroying a library and office in his compound and badly damaging a reception hall for visiting dignitaries.

Gadhafi’s whereabouts at the time of the attack on his sprawling Bab al-Aziziya compound were unclear. A security official at the scene said four people were lightly hurt.

Today’s strike came after Gadhafi’s forces unleashed a barrage of shells and rockets at the besieged rebel city of Misrata in an especially bloody weekend that left at least 32 dead and dozens wounded.

The shelling of the only major city in western Libya in rebel hands continued early this morning.

The battle for Misrata, which has claimed hundreds of lives in the past two months, has become the focal point of Libya’s armed rebellion against Gadhafi since fighting elsewhere is deadlocked.

In Brussels, a NATO spokesman said the alliance is increasingly targeting facilities linked to Gadhafi’s regime with government advances stalled on the battlefield.

Gadhafi’s son, Saif al-Islam Gadhafi, struck a tone of defiance. He claimed Gadhafi has “millions of Libyans with him” and said NATO’s mission was doomed to fail.