As of yesterday 27 soldiers and nearly 20 Palestinian fighters had been killed. At least 57 civilians have been wounded and some have been killed though the exact number remains unknown because of restrictions on who may enter the camp placed by the Lebanese army. Palestinian political leaders and refugee public opinion largely supports the Lebanese army, though growing civilian casualties may hinder this support. All the major Lebanese factions including Hizbu'llah have backed the army as well.
Fatah al-Islam is reportedly one of the Sunni extremist groups which have received funding since last year from the Lebanese government, headed by the dinosaur bureaucrat Fu'ad Siniora and backed by the oily Sa'ad al-Hariri, son of the corrupt former prime minister Rafiq al-Hariri. Where did these funds come from? Reportedly from an aid package sent to the Lebanese government by the U.S. in the hopes that if they supported Sunni groups they could chip away at the support of the Shi'i Lebanese party Hizbu'llah.
Sending money to Sunni radicals in the hopes that they will further one's political goals only to have it backfire on you...sounds familiar.