JERUSALEM -- The Israeli military said it downed a drone launched by militants in the Gaza Strip on Monday, the first time it encountered an unmanned aircraft since the start of its offensive last week, as new Israeli airstrikes pushed the death toll from a weeklong Israeli offensive to at least 175.
Israel began its campaign against militants in the Hamas-controlled Gaza Strip last Tuesday, saying it was responding to heavy rocket fire from the densely populated territory. The military says it has launched more than 1,300 airstrikes since then, while Palestinian militants have launched nearly 1,000 rockets at Israel.
The use of the unmanned drone marked a new and unexpected tactic by Hamas, which has never before acknowledged having such weapons. Although it was quickly shot down, the drone represented a new level of sophistication for the militant group. In the past, Hezbollah militants in Lebanon have sent at least one drone into Israel that also was shot down.
The Israeli military said the drone was shot down in mid-flight by a Patriot surface-to-air missile along the southern Israeli coastline, near the city of Ashdod.
A senior military official said that Israel was aware that Hamas possessed drones, and that Israel has targeted Hamas drone facilities in Gaza before. Speaking on condition of anonymity under military guidelines, he would not say how far the plane flew or discuss its capabilities.
In a statement to media, Hamas claimed it launched three drones at Israel on Monday, though the military insisted there was only one. Hamas released a video of what it said was the aircraft, about five meters (yards) long, with each wing holding two unidentified missiles. The veracity of the video could not be independently confirmed.
Drones can refer to a range of unmanned aircraft, ranging from rudimentary airplanes to advanced aircraft capable of firing weapons or conducting sophisticated surveillance missions.
Hamas said it has developed two types of drones - one for intelligence gathering, and one for delivering munitions. It also said it lost contact with one of the drones and that the targets included the Israeli Defense Ministry compound in Tel Aviv.
It was the first time the militant group publicly acknowledged it has drones in its arsenal.
The use of drones with an offensive capacity could inflict significant casualties - something the rockets from Gaza have failed to do, largely because of the success of the Israeli military's 'Iron Dome' air defense system in shooting them down.
"Hamas is trying everything it can to produce some kind of achievement and it is crucial that we maintain our high state of readiness," Israeli Defense Minister Moshe Yaalon said. "The shooting down of a drone this morning by our air defense system is an example of their efforts to strike at us in any way possible."
The Israeli military said it hit a weapons storage facility late Sunday night, and targeted 12 Palestinian militants over the last 24 hours, reports CBS News' Holly Williams, but at the al-Sharif Hospital in Gaza on Monday morning, CBS News found not militants, but two brothers -- four-year-old Hamada and two-year-old Hamadan.
They were injured when an airstrike hit their neighbor's house.
Their father, Mohammed, told CBS News the Israeli military telephoned the neighbor to warn them to evacuate, but they only had three minutes and didn't make it out in time.
"I wish it were me lying here wounded, not my boys," the father said.
Fighting continued Monday as two Israeli airstrikes struck the southern Gaza city of Khan Younis, killing four Palestinians, according to officials from the city's European Hospital.
The officials said Saddam Moamar, his wife Hanadai, and his father Mousa were killed by an airstrike that hit their house. Their neighbor, Maher Abu Mor, was killed in another airstrike while standing on the rooftop of his home, the officials said, speaking on condition of anonymity because they were not authorized to talk to media.
It was not immediately clear why their homes were targeted.
In all, the Palestinian Health Ministry in Gaza has said that at least 175 people have been killed in Israeli air attacks, including dozens of civilians.
No Israelis have been killed as a result of Hamas rocket launches. Several people have been wounded, however, including a teenage boy who was seriously injured by rocket shrapnel on Sunday.
Israeli Prime Minister Benjamin Netanyahu said Sunday that the current Israeli operation could last for "a long time" and that the military was prepared "for all possibilities." That includes a Gaza ground operation, which would likely cause heavy casualties in the coastal strip.
But Netanyahu is coming under increasing international pressure to end the operation soon. On Sunday, U.N. Secretary-General Ban Ki-moon called for an immediate cease-fire while U.S. Secretary of State John Kerry voiced American "readiness" to help restore calm. Egypt, a key mediator between Israel and Hamas, continued to work behind the scenes to stop the conflict.
Hamas has sent signals it may be ready to consider a cease-fire and has demanded that hundreds of recently arrested activists be freed as part of any prospective truce.
For his part, Netanyahu is likely seeking to show the Israeli public that he has succeeded in significantly degrading Hamas's ability to strike at Israeli targets before moving ahead diplomatically.
Also Monday, a 21-year-old Palestinian was killed during confrontations with Israeli soldiers in the West Bank village of Samoa, near Hebron, Palestinian health officials said. Residents of the village said soldiers opened fire at a group of Palestinians who were throwing stones at them. The officials and the villagers spoke on condition of anonymity because they were not authorized to talk to media.
The Israeli army confirmed the death and said it was looking into the incident.
The outbreak of violence followed the kidnappings and killings of three Israeli teenagers in the West Bank last month, as well as the subsequent kidnapping and killing of a Palestinian teenager in an apparent revenge attack, along with Israeli raids against Hamas militants and infrastructure in the West Bank.
Israel's Shin Bet security service on Monday released the findings of its investigation into the killing of 16-year-old Mohammed Abu Khdeir, whose death set off days of violent protests in Arab areas of Jerusalem and northern Israel. The detention of the three main suspects in the case, a 29-year-old man and a pair of 17-year-olds, was extended until Friday as they appeared before a court, officials said.
Shin Bet said the suspects, whose names were not released, were motivated by revenge following the killing of the Israeli teenagers. During the investigation, the three admitted to abducting Abu Khdeir and setting him on fire, according to the security agency. They also re-enacted the murder. Four others were being investigated and remained under house arrest for their involvement in the killing, it said.
Abu Khdeir was taken on July 2 near his home in east Jerusalem and his charred body was later found in a forest. An autopsy found that he was burned to death.
Israeli leaders widely condemned the killing and Prime Minister Benjamin Netanyahu vowed those responsible would be brought to justice.
Israel has yet to capture the killers of the three Israel teenagers. It accuses Hamas and cracked down on the Islamic militants in the West Bank after the teens' abduction, contributing to an increase in rocket fire from Gaza that ultimately led to the current round of fighting.