Israeli Prime Minister Benjamin Netanyahu vowed to avenge what he said was a “black day” for Israel Saturday, saying the army will strike back at Palestinian militant group Hamas in Gaza with full force.

“The IDF (army) is about to use all its force to destroy Hamas’s capabilities,” Netanyahu said in a brief televised statement.

“We’ll strike them to the bitter end and avenge with force this black day they brought on Israel and its people,” he said, after Hamas militants launched a surprise dawn attack, sending hundreds of militants into Israel under cover of a huge rocket barrage.

Gun battles raged into the night after Hamas’ large-scale attack against Israel Saturday, firing thousands of rockets from Gaza and sending fighters to kill and abduct soldiers and civilians.

The attack signals the first of such combined ground, air and sea offensive, half a century after the outbreak of the 1973 Arab-Israeli war.

“We are at war,” Netanyahu told the stunned nation as the army retaliated by pounding targets in the blockaded enclave, where several residential tower blocks were reduced to rubble.

About 80 people were killed in Israel, medical services said, while Gaza authorities released a death toll of 232 in the conflict’s bloodiest escalation in years which also left many hundreds wounded on both sides.

“The enemy will pay an unprecedented price,” Netanyahu vowed. (AFP)