Although Israel has delayed its ground offensive amid global calls for a ceasefire, the military continued its airstrikes, killing six people on Monday.
The Israeli military said that it shot down the drone spotted along the Israeli coastline, near the city of Ashdod.
Hamas' military wing said in a statement that it has sent a number of drones on missions inside Israel and would provide more details in due course.
About 17,000 people from the Beit Lahiya area in the northern Gaza Strip streamed for protection into the United Nations-run facilities after Israel on Sunday warned residents of the area to leave their homes.
Israeli warplanes bombarded the vacated area, hitting alleged launch sites and homes of members of extremist groups such as Hamas and Islamic Jihad. The assault was carried out mostly by air, but the Israeli navy also reportedly fired shells from the sea.
Despite the concentrated attack, militants continued to fire rockets at a broad swath of Israel. A teenager became the second Israeli civilian to be severely wounded. No Israelis have been killed by the rocket strikes.
Israeli air strikes on Monday hit three training facilities of Hamas's military wing and buildings in Gaza city, causing injuries.
By this morning, the death toll from nearly a week of Israeli airstrikes reached 177 -- all of them Palestinians -- with more than 1,280 wounded, according to Palestinian health authorities.
While the Israeli attacks have killed some militants, around 70 per cent of the fatalities were civilians, according to the United Nations. Of the dead, more than 30 are children, the UN reported.
Israel has massed thousands of troops on the border with Gaza amid warnings it is prepared to launch a ground invasion. Israeli commandos carried out their first reported ground incursion on Sunday, attacking a suspected rocket launch site.
Israel has so far shrugged off international calls for a ceasefire, saying it will continue the offensive as long as the militant group Hamas keeps firing rockets into its territory.
Defending Israel's actions, Prime Minister Benjamin Netanyahu said, "We're sorry for any accidental civilian deaths but it's the Hamas that bears complete responsibility for such civilian casualties."
Foreign Minister Avigdor Lieberman said all options are on the table and warned against a temporary fix to the situation.
Israel said its forces have struck 1,470 "terror targets" across Gaza, including 770 concealed rocket launchers.
International efforts are on to press Israel and Hamas into negotiating a ceasefire.
German Foreign Minister Frank-Walter Steinmeier will hold meetings in the region in the coming days to find out a solution to the crisis.
The UN Security Council has called for a ceasefire and renewed peace talks between Israel and the Palestinians. UN chief Ban Ki-moon has asked Israel to scrap plans for the ground offensive, saying "too many" Palestinian civilians have lost their lives.
The current wave of violence followed the killing of three Israeli teenagers in June and the suspected revenge killing of a Palestinian teenager in Jerusalem. Meanwhile, Israeli officials on Monday said three arrested
Israeli Jews had now confessed to the murder of the Palestinian, Mohammed Abu Khdair.
Image: A Palestinian woman reacts in front of the remains of her house, which police said was destroyed in an Israeli air strike, in Rafah in the southern Gaza Strip. Photograph:
Ibraheem Abu Mustafa/Reuters
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