Israel's war with Hamas erupted again yesterday, as airstrikes hit houses and buildings in the Gaza Strip minutes after a weeklong truce expired. Health authorities in the besieged territory reported dozens of Palestinians killed and Israel dropped leaflets over Gaza City and southern parts of the enclave, urging civilians to flee to avoid the fighting.<br />''<br />''Militants in Gaza resumed firing rockets into Israel, and fighting broke out between Israel and Hezbollah militants operating along its northern border with Lebanon. Renewed hostilities also heighten concerns for about 140 hostages still held captive by Hamas and other militants, after more than 100 were freed during the truce. The Israeli army yesterday confirmed the deaths of five hostages held in Gaza, saying their families had been informed, and the body of one of them returned to Israel. <br />