An Israeli soldier was severely wounded by Palestinian fire along the Gaza border early on Tuesday, just hours before a high-profile visit to the strip by the Qatari emir, the military said.
Although the army did not say how he was hurt, military sources suggested it may have been the result of an explosive device.
"A soldier was severely wounded during a routine patrol along the fence in the Kissufim area," a military spokeswoman said of the incident which occurred near central Gaza shortly before 7:00 am (0500 GMT).
Military sources said his injuries were "definitely caused by Palestinian fire," telling AFP: "We are checking the possibility that was an explosive device."
Hamas security sources told AFP the explosion occurred during an incursion by Israeli forces into Gaza territory.
"The IDF (army) will not tolerate any attempt to harm Israeli civilians, and will operate against anyone who uses terror against the state of Israel," a military statement warned.
"Terror organisations continue their relentless attempts to harm Israeli civilians and IDF soldiers by using the area adjacent to the security fence for laying explosive devices and attempting to execute terror attacks," the statement added.
It added that an explosive device was detonated a week ago against soldiers patrolling along the fence, damaging a military vehicle.
Tuesday's incident came just hours ahead of the arrival of Qatari Emir Sheikh Hamad bin Khalifa al-Thani who was due to cross from Egypt into southern Gaza at 11:00 am (0900 GMT), in what will be the first visit by a head of state since the Islamist Hamas movement forcibly took over the territory in 2007.
On Monday morning, Israeli troops patrolling the border clashed with Palestinian militants, prompting a series of air strikes which according to medics left two dead and four critically wounded.
Palestinian witnesses said Monday's incident too had occurred after troops crossed onto the Gaza side of the border.