Gaza An Egyptian-brokered truce between Israel and fighter groups in the Gaza Strip began to take hold Tuesday after four days of violence in which 25 Palestinians were killed and 200 rockets were fired at Israel.

The number of Palestinian rocket attacks dropped sharply after the ceasefire went into effect overnight, and no major towns in southern Israel were targeted.

The Israeli military said six projectiles had hit, causing no casualties, and that there had been no Israeli air strikes in the Gaza Strip.

Previous ceasefire deals after earlier rounds of fighting have often got off to a slow start, with guns gradually falling silent within a day or two.

A senior Egyptian security official in Cairo told Reuters by phone that both sides had agreed "to end the current operations", with Israel agreeing to "stop assassinations", and an overall deal "to begin a comprehensive and mutual [period of] calm".

"We expect this ceasefire to continue but we cannot be sure so our forces ... are ready to continue if it will end up being necessary," Israeli Defence Minister Ehud Barak, visiting southern Israel, told reporters.

The anti-missile batteries destroyed dozens of incoming rockets, but the barrages disrupted normal life for more than a million Israelis in the south, forcing schools to close and people to run for cover.