GAZA CITY -- Israeli tanks moved into the Mughazi refugee camp in central Gaza early today under cover of machine-gun fire from troops.
It was the latest incursion in its three-week military push in Gaza.
The Israeli military confirmed that an operation was in progress.
Palestinians said a Hamas gunman had been killed by Israeli machine-gun fire as he tried to fire a rocket at Israeli tanks. Earlier, another Hamas militant was seriously wounded.
The camp, with 22,000 residents, is near the Gaza-Israel fence, and is across from the Palestinian town of Deir al-Balah. Israeli forces operated in the region last week before withdrawing.
Israeli troops have also swept through southern Gaza and have carried out two invasions of northern Gaza, in an effort to stop militants from firing rockets at Israel.
The move into Mughazi was preceded by tank movements on the Israeli side and exchanges of fire between soldiers and Palestinian gunmen. Palestinian officials said a Hamas militant had been seriously wounded.
Israel began a large-scale operation in Gaza on June 28, three days after militants aligned with Hamas had tunneled under the border and attacked an Israeli Army base at a Gaza crossing, killing two soldiers and capturing a third Israeli soldier.
The military said early today that it had opened two crossings into Gaza yesterday to allow shipments of food and fuel.