JERUSALEM, Dec 27 Israel`s air attack on the Gaza Strip on Saturday could signal a return to a much higher level of violence in the conflict with Palestinian Islamist group Hamas after nine months of lower-level confrontations.

The peace process with Israel, already in a coma in the last days of George W. Bush`s presidency in the United States, could be killed off by renewed violence.

Several factors point to the likelihood of violence worsening following a series of Palestinian rocket attacks since Hamas ended a ceasefire just over a week ago.

* Israel`s Defence Ministry signalled it was ready to pursue and widen actions against Hamas in Gaza, including targeting the militant group`s leaders, and made clear it was preparing for a potentially long campaign.

“We face a period that will be neither easy nor short, and will require determination and perseverance until the necessary change is achieved in the situation in the south,” Defence Minister Ehud Barak said.

* The mayor of Ashkelon, the Mediterranean coastal city in range of Hamas`s Grad rockets, said he was told by Israeli military planners that the operation would last for “more than a week”.

* Israeli military analyst Ron Ben-Yishai said the strike was “shock treatment ... aimed at securing a long-term ceasefire between Hamas and Israel on terms that are favourable to Israel”. It was meant to make it clear to Hamas that Israel would respond “disproportionately” every time rockets harm Israelis.

Ben-Yishai foresaw a rain of rockets on south-western Israel and “on a wider front, we can assume that Hamas will attempt to dispatch members ... to carry out suicide attacks in Israel”.

* Hamas quickly vowed revenge, ordering “all fighters to respond to the Israeli slaughter”. It did not say what form this action would take but one fighter maddened by the sight of the mangled bodies of his comrades said suicide bombers would blow themselves up in Israeli restaurants, cafes and streets.

Hamas leaders left the door open to a strong response, saying their movement was popular and deeply rooted. “All options are open to the Palestinian resistance to strike the Zionist enemy,” a statement said. “One leader will be replaced by a hundred leaders.”—Reuters