Palestinian witnesses on Sunday said one of the missiles hit the main power transformer, causing a power blackout in the camp of 80,000 refugees.
The other four missiles landed in an area next to the border with Egypt where Israeli occupation forces had razed homes earlier in the day.
Medics said ambulances were trying to get to the blast sites to search for possible casualties but darkness from the blackout was hindering their efforts.
Israeli military sources confirmed missiles were fired and said it was a preventative measure to repulse resistance groups preparing to attack an army position.
Israel has carried out many aerial missile strikes and ground offensives in Gaza and the West Bank in almost continuous campaigns to crush Palestinians in revolt since 2000.