The Israeli army has conducted airstrikes on the Palestinian enclave now controlled by the Islamist movement in response to frequent rocket and mortar attacks on Israeli territory.
According to Israeli officials, Palestinians fired at least 240 rockets and mortar shells at nearby Israeli provinces in November alone.
An Israeli airstrike on Tuesday killed at least three Hamas fighters in Gaza's coastal town of Deir el-Balah.
Tel Aviv has urged Palestinian authorities to put a stop to attacks by militants against Israel before any peace deal can be brokered.
Gaza broke away from the West Bank controlled by President Mahmoud Abbas after violent clashes between Hamas and pro-presidential Fatah in June.
The Palestinian enclave has since been hurt by severe economic restrictions imposed by Israel.
The UN's latest humanitarian fact sheet on Gaza says that about 75% of the territory's population relies on food aid to survive. And import restrictions have led to the suspension of more than $200 million worth of humanitarian programs, including sanitation projects, the press spokesperson for the UN secretary general said on Tuesday.
Michelle Mantos also said deaths among newborns in Gaza this year are 20% higher than in 2006, and unemployment has soared past 32%.
Rights groups have warned the increase in poverty and dependency will lead to a further radicalization of Gaza's population, driving more people into the hands of extremists and causing further violence.
