The only power station in the Gaza Strip has reportedly been shut down due to a retaliatory campaign by Israel, causing mounting concerns over a worsening humanitarian crisis.

Exchanges of attacks have continued since the Palestinian Islamist group Hamas launched a massive offensive against Israel on Saturday. The death toll has topped 2,300 -- 1,200 in Israel and 1,100 in Gaza.

Israel published footage purported to show the country carrying out airstrikes and long-range missile attacks on a local university and other buildings in Gaza, destroying them. Israel says the buildings served as Hamas military bases.

An increasing number of citizens have been victimized in the Gaza Strip by Israel's retaliatory campaign.

The Palestinian Authority says Israel is using white phosphorus bombs, which international critics say are inhumane because they cause serious burns.

Palestinian media say the only power station in Gaza has shut down due to a fuel shortage caused by what Israel calls "a complete siege" of Gaza.

The World Health Organization warns that hospitals in Gaza may run out of fuel for backup generators in the coming days. It is calling for humanitarian corridors to be set up to deliver medical and other necessary supplies.