Israeli warplanes struck the southern part of the Gaza Strip in an overnight raid following Palestinian rocket fire, Palestinian witnesses and the Israeli military said on Monday.
The aircraft attacked a tunnel on the Rafah sector on the border with Egypt, but no one was injured, said witnesses.
A military spokesman confirmed the raid, saying they had hit a tunnel used for arms smuggling and in response to rocket fire from the Palestinian side.
One rocket was fired into southern Israel late Sunday from the Hamas-controlled Gaza Strip though it landed without causing any injuries or damage, the Israeli army said earlier.
That brought the total number of rockets fired since Thursday to nine, the army said, one of which killed a Thai farm worker in southern Israel.
Israeli warplanes have struck back with a series of air strikes on the Gaza Strip. So far the raids have slightly injured two people.
According to army figures, Palestinian militants have fired around 150 rockets and 75 mortar shells at Israel since the end of the devastating 22-day Israeli offensive against Gaza launched in December 2008.
The militant group Hamas seized control of the Gaza Strip from the Fatah group of Palestinian Authority leader Mahmud Abbas in June 2007.