Prime Minister Benjamin Netanyahu said Monday that Israel would respond to every Qassam rocket fired from the Gaza Strip, hours after the Israel Air Force planes bombed a tunnel along the border.
The raid was launched in response to Sunday's mortar and rocket attacks from Gaza against Israel, an IDF spokeswoman said.
There were no immediate reports of casualties from the pre-dawn raid in the Palestinian coastal territory, ruled by the Islamist Hamas movement.
The spokeswoman said the strike targeted a tunnel under the town of Rafah suspected of being used to smuggle explosives into Gaza from Egypt.
Israel has frequently attacked tunnels it says are used to smuggle weapons or materials to build weapons, though such raids have occurred less frequently in the past few months.
On Sunday, Gaza militants fired mortars at a crossing into Israel just as Palestinian patients were being transferred for treatment, a Palestinian official said.
"It's a miracle nobody was hurt," Health Ministry official Dr. Moaiya Hassanain said.
Two radical Palestinian groups, the Popular Front and the Democratic Front, said they fired 12 mortars at the Erez crossing. The Israel Defense Forces said about six shells exploded near the Erez crossing as the transfer was in progress.
According to the procedure, the Palestinian patients are brought to the crossing in local ambulances and transferred to Israeli ambulances for their trips to hospitals.
Earlier Sunday, a Qassam rocket fired from the Gaza Strip struck an open area adjacent to one of the communities in the Sdot Negev area. No one was hurt and no damage was caused.
This attack was the first such strike in almost a month. The last rocket to hit Israel also struck an open area in the Sdot Negev area.
At the end of May, an 18-year-old Israeli sustained minor wounds when a rocket struck the yard of his home in the Negev town of Sderot. Two other women suffered shock in the same incident.
Last week, the organization Human Rights Watch released a report arguing that Hamas committed war crimes against Israel by besieging it with rockets during the three-week war in the Gaza Strip earlier this year.
The 31-page report focusing on Operation Cast Lead, spotlights Hamas, after Human Rights Watch and similar groups have repeatedly accused Israel of committing war crimes.
"Hamas forces violated the laws of war both by firing rockets deliberately and indiscriminately at Israeli cities and by launching them from populated areas and endangering Gaza civilians," HRW program director Iain Levine said.
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