Israeli airstrikes in Gaza intensified on Saturday night, destroying residential buildings including a 14-storey tower block.Israel's Prime Minister Benjamin Netanyahu has warned people living in Gaza to leave as he vowed to turn parts of the territory "into ruins".Mr Netanyahu earlier declared Israel was at war after Hamas militants broke out of the blockaded Gaza Strip on Saturday to launch an early-morning attack.

Israeli airstrikes in Gaza intensified on Saturday night, destroying residential buildings including a 14-storey tower block.Israel's Prime Minister Benjamin Netanyahu has warned people living in Gaza to leave as he vowed to turn parts of the territory "into ruins".Mr Netanyahu earlier declared Israel was at war after Hamas militants broke out of the blockaded Gaza Strip on Saturday to launch an early-morning attack.