GAZA CITY, Gaza Strip » Palestinian police say at least six people have been killed when an overnight Israeli airstrike hit a densely populated neighborhood in the Gaza Strip.

Police say the strike early on Thursday destroyed a four-story structure in the southern town of Rafah and that rescue workers were still searching for people trapped in the rubble.

The strike was one of 20 the Israeli military says were carried out since midnight on Wednesday.

It followed the breakdown of Egyptian-mediated talks aimed at producing a long term truce after more than a month of fighting that has killed more than 2,000 Palestinians, mostly civilians. Israel lost 67 people, all but three of them soldiers.

Israel says the airstrikes are in response to a resumption of Hamas rocket launches that ruptured the cease-fire Tuesday.