According to witnesses, Israeli aircraft fired two rockets at a group of Hamas fighters who were approaching the Nahal Oz border crossing on Sunday evening.
A similar attack on Gaza occurred two days earlier involving a group armed with rockets from the Popular Front for the Liberation of Palestine.
A six-month ceasefire agreement, which runs out this Thursday, almost collapsed at the beginning of November when Israel renewed military operations in the Gaza Strip in response to Palestinian militant activity, prompting an increase in rocket strikes against Israel.
Palestinian militant groups doubt that the ceasefire will be extended. Israel is interested in prolonging the truce as it is with no further talks or conditions, while refusing to expand it to include the West Bank, according to Israeli radio reports.