Jerusalem ? Prime Minister Ehud Olmert threatened a painful response to Palestinian rocket fire menacing southern Israel, suggesting Sunday that the blistering offensive against Gaza Strip militants fell short of its goals.

The prospect of heightened hostilities in Hamas-ruled Gaza cast a pall over a week of crucial diplomatic activity, including an international conference designed to drum up billions of dollars to rebuild the heavily damaged territory. With a new Israeli government to take office within weeks, however, it wasn’t clear how sweeping the country’s response to the rockets would be.

More than 110 rockets and mortar shells have exploded in Israel in the six weeks since it ended its air and ground onslaught against Gaza, which was meant to end the rocket threat and stanch the flow of arms into Gaza. So far, Israel has responded to the rocket fire mainly with airstrikes targeting underground tunnels used to smuggle weapons and other goods into Gaza from Egypt.

The rockets “will be answered with a painful, harsh, strong and uncompromising response from the security forces,” Olmert said at the start of the weekly Cabinet meeting.

There was no comment from Hamas or other Gaza militant groups. Several hours after Olmert spoke, a rocket exploded in southern Israel, causing no injuries.