Such attacks as those that hit the area Thursday may force Israel to alter its plans and return to the Gaza Strip, the ministry said in a statement.

"Israel left the Gaza Strip over two years ago with no intention of ever returning," the statement said, as reported by IsraelNN.com.

"Yet, the continued escalation of Hamas terrorism emanating from Gaza, purposely targeting Israeli civilians, is liable to leave Israel with no choice" but to return and settle the region.

"In the past 24 hours, over 15 heavy rockets were fired from Hamas-controlled Gaza against Israel's southern port city of Ashkelon," the statement said, pointing a finger at Tehran.

"The Grad rockets fired today were apparently smuggled into Gaza from Iran via Egypt through tunnels and the breached Rafah border fence," the ministry said.

"Israel has repeatedly warned neighboring states and the international community about the arms buildup taking place in Hamas-controlled Gaza."

Thursday's missiles slammed into the campus of Barzilai Hospital, destroyed a family home in the port city, created a large crater in a city street and struck the municipal cemetery, IsraelNN.com reported.