A Palestinian Hamas-hired civil servant receives her salary paid by Qatar, in Khan Younis in the southern Gaza Strip, Dec. 7, 2018. Photo: Reuters / Ibraheem Abu Mustafa.

An Israeli tank fired into the Gaza Strip on Tuesday, killing a Hamas fighter in what the army described as retaliation for the wounding of a soldier and a brief incursion during a violent Palestinian border protest.

An Israeli official said Prime Minister Benjamin Netanyahu also canceled a Qatari donation of $15 million for the impoverished enclave that had been due on Wednesday as part of international efforts to head off escalation in Gaza.

Palestinian medics in Gaza said a Hamas fighter died and two others were wounded in the Israeli shelling of a lookout post near the fortified frontier in the central sector of the enclave ruled by the Islamist group.

Hamas confirmed the three casualties as its members.

Earlier on Tuesday, the army said in a statement, one of its officers was shot at as he faced Palestinian rock-throwers at the fence. The bullet struck his helmet, lightly injuring him, the army said, adding that during the incident two Palestinians also crossed into Israel before returning to Gaza.

Worried about a potential flare-up into full conflict, Egypt and the United Nations have sought to calm Gaza, while Qatar in November pledged $150 million in donations, to be transferred via Israel over six months, in hope of easing economic pressure.

A third Qatari payout of $15 million was due on Wednesday, after it was previously held up by Israel in protest at border violence. An Israeli official, announcing the new postponement, did not say when the payout might now take place.