Israeli aircraft have carried out night airstrikes on Gaza after Palestinian militants battered southern Israel with rockets in a further night of fighting.
Israel said it had carried out raids on eight targets in the Gaza Strip, including a training center used by militants from the Hamas armed wing, the Ezzedine al-Qassam Brigades.
By Wednesday morning militant Palestinians had fired at least 10 rockets into Israel from the Gaza Strip.
As the violence entered a third day, Israel increased its level of alert in the area within rocket range of the Gaza Strip. Nearly 50 rockets have struck Israel since Tuesday, the country's military said.
"We have raised our level of alert and reinforced patrols in areas near the Gaza Strip," said police spokesman Micky Rosenfeld.
Around a million people live in that part of southern Israel.
Few casualties, so far
Six Palestinians have been killed and five injured since the violence began on Monday morning. Palestinian officials said there had been no casualties in the most recent airstrikes.
In Israel, four police officers were wounded when a rocket ploughed into a border police outpost in Yad Mordechai, Rosenfeld said.
Palestinian militants began the attacks on Monday, which Israel has answered with airstrikes.
Islamic Jihad said a truce would come into effect on Tuesday at midnight, but neither side heeded it.
It is the worst flare-up of violence between the two parties in months.
ncy/ccp (Reuters, AFP, AP, dpa)