Airstrikes and rockets kill 10 people in the Gaza Strip region

The Israeli armed forces and militants based in the Gaza Strip exchanged attacks Saturday in a sharp escalation of violence that killed nine Palestinians and one Israeli.

Palestinian sources said five Islamic Jihad militants were killed in an initial Israeli airstrike near Rafah in the southern Gaza Strip, including a prominent maker of rockets. Israeli news reports said the airstrike targeted a cell responsible for launching a rocket into Israel recently.

The army said the strike was not in retaliation for an attack, but was instead a preventive action.

A few hours later, a barrage of about 20 rockets began landing in southern Israel, some making direct hits on residential buildings and setting cars and property on fire. One rocket landed in a school in the city of Ashdod that was closed for the Sabbath.

Islamic Jihad claimed responsibility for the attacks.

Two additional Israeli airstrikes killed four more Islamic Jihad members, Palestinian sources said. One Israeli was killed, according to Israeli news reports, and several injured people were taken to hospitals.

The spate of violence in recent days broke a cease-fire agreement that largely had held since August. It came just days after international negotiators visited Israel and the Palestinian territories to try to restart peace talks.

Prime Minister Benjamin Netanyahu spoke to mayors of communities that were targeted in southern Israel, promising that the military response would get tougher, if necessary, according to a statement from the prime minister's office early Sunday.

Speaking at a news conference in Bosnia-Herzegovina, Foreign Minister Avigdor Lieberman said that Israel was not looking for a confrontation with the Palestinians but that it would "not take one barrage after the other without response."

Saturday's increase in violence came less than two weeks after a prisoner exchange between Hamas, which rules Gaza, and Israel.

Israeli soldier Gilad Shalit, who had been held for more than five years, was freed Oct. 18. Israel agreed to release more than 1,000 Palestinians, about half of whom already are free.

Some in Israel, including opposition leader Tzipi Livni, warned that the deal would bolster the standing of Hamas. In a statement Saturday, Livni urged Israel to weaken "radical terror elements such as those behind the rocket attacks through direct action as well as a "diplomatic process with the moderate elements who do not employ violence."