Israel will intensify its actions against rocket attacks launched from the Gaza Strip, Premier Ehud Olmert said Sunday, as an Israeli raid into the central salient killed at least three people after militants fired 42 mortars and 16 rockets at the Jewish state over the weekend.

The Israeli raid on the vicinity of the el-Bureij refugee camp in the central Strip began before dawn Sunday.

A 17-year-old Palestinian teenager was killed when troops opened fire as they approached the area, and two women were killed by an Israeli artillery shell in the afternoon, Palestinian officials said.

A Palestinian gunman was killed in an earlier Israeli air raid. Five Israeli soldiers were wounded in the fighting sparked by the Israeli incursion.

Israel launches almost daily raids into the Gaza Strip in a bid to prevent militants from launching rockets and mortars at adjacent Israeli towns and villages.

The rockets, over 2,000 of which were launched last year, are makeshift Qassam rockets, with a range barely exceeding 11 kilometres, and cause limited damage and almost no fatalities.

But they induce panic, fear and shock among their intended targets, and the Israeli government is coming under increasing pressure to find a way to put a stop to them.

On Thursday, militants launched a long-range 122-mm Grad missile at the city of Ashqelon, which lies about 15 kilometres north of the Strip - a move Olmert described Sunday as an "intensification and escalation"in the rocket attacks.

"Defence Minister (Ehud) Barak has ordered security forces to intensify the Israeli response ... our security forces will continue to both respond ands take the initiative," an Israeli communique quoted Olmert as telling his ministers at Sunday's weekly cabinet session in Jerusalem.

The last upsurge in Israeli-Palestinian clashes comes only days before President George W Bush is due to land in Israel and the Palestinian areas at the start of a regional trip which will also see him visit Kuwait, Bahrain, the United Arab Emirates, Saudi Arabia and Egypt.

The Israeli Ha'aretz daily reported Sunday that Israel and the Palestinians will renew negotiations over the core issues of their conflict following the visit.

The talks will be conducted by a special committee headed by Israeli Foreign Minister Tzipi Livni and former Palestinian prime minister Ahmed Qureia. Non-core issues will be discussed by other committees.

Previous negotiations over the core issues - Jerusalem, the future of Palestinian refugees and their descendents, the borders of the future Palestinian state - were conducted by separate committees and ended in failure. They have not been renewed since early 2001.

Bush is slated to arrive on Wednesday afternoon, and visit Israel and the West Bank for talks with Israeli and Palestinian leaders.

He will not visit the Gaza Strip, which is administered by the Islamist Hamas movement which seized control of the enclave in June last year, and which rejects a two-state solution to the Israeli- Palestinian conflict in favour of an Islamic state in all of historic Palestine.

A Hamas spokesman slammed the Bush visit, saying the president's hope of creating a Palestinian state was "an illusion."

The radical Islamic Jihad faction, which is behind most of the rocket launches from the Gaza Strip, said for its part that the presidential visit would only widen internal Palestinian divisions "and provide cover for the Israeli occupation's crimes in Gaza Strip and West Bank as part of maintaining Israel's security at the expense of the Palestinian interest.

Bush's visit to Israel and the Palestinian areas, his first to as as president, follows November's Middle East summit in Annapolis, Maryland, where Israeli Prime Minister Ehud Olmert and Palestinian President Mahmoud Abbas pledged to try reach a peace accord by the end of 2008.