Israeli aircraft attacked Gaza on Saturday for the first time since an August truce ended a 50-day conflict after a rocket hit the Jewish state, witnesses and the army said.

A Palestinian Health Ministry spokesman in Gaza said no one was injured in the airstrike. The attack came just hours after the rocket hit an open field in southern Israel on Friday without causing casualties or damage.

It was the third time a rocket fired from the Palestinian enclave landed within Israel since the Aug 26 truce between Israel and Palestinian Islamist movement Hamas, the territory's de facto ruler.

The Israeli army said the airstrike in the southern Gaza Strip had "targeted a Hamas terror infrastructure site".

Israeli Defense Minister Moshe Yaalon said the target was a concrete factory being used to repair tunnels in and out of Gaza, dozens of which Israel destroyed during the summer campaign.

The attack was "an unequivocal message to Hamas that we will not tolerate a return to a routine of sporadic firing at our citizens," Yaalon said, vowing Israel would "act forcefully" against Hamas "if it won't prevent attacks".

Israeli Prime Minister Benjamin Netanyahu reiterated that his government would not ignore "even one rocket launched" at its territory.

"Hamas will bear the consequences of any escalation that might take place," he told soldiers at a ceremony in remarks distributed by his office.

Hamas did not say it was behind the rocket attack, but Israel holds it accountable for any rocket fire from Gaza.

Gaza's Hamas leader Ismail Haniya condemned Israel's "dangerous violation of the cease-fire", and urged Egypt to "move with urgency" to ensure the Jewish state respects the agreement.

The summer conflict between Israel and Hamas killed almost 2,200 Palestinians, most of them civilians, and 73 people on the Israeli side, nearly all of them soldiers.

The Egypt-brokered cease-fire was to have been followed by talks on a more lasting truce, but they were called off amid deteriorating ties between Cairo and Hamas.

Also on Saturday, the Israeli navy fired warning shots after fishing boats sailed beyond the six nautical mile limit enforced by Israel off Gaza's coast.

A military spokeswoman said the vessels returned to waters where the navy allows them to operate.

AFP - Xinhua

(China Daily 12/22/2014 page11)